Add packages to optimize svgs dynamically

These packages will be used to dynamically optimize SVG images
during the build.

R=jacktfranklin@chromium.org

Bug: 1216402
Change-Id: I04e95aa7d79c9d67beaf8a7861182c52b16b7d0f
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2939992
Reviewed-by: Jack Franklin <jacktfranklin@chromium.org>
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
diff --git a/node_modules/css-tree/lib/tokenizer/char-code-definitions.js b/node_modules/css-tree/lib/tokenizer/char-code-definitions.js
new file mode 100644
index 0000000..fb9ec3f
--- /dev/null
+++ b/node_modules/css-tree/lib/tokenizer/char-code-definitions.js
@@ -0,0 +1,249 @@
+var EOF = 0;
+
+// https://drafts.csswg.org/css-syntax-3/
+// § 4.2. Definitions
+
+// digit
+// A code point between U+0030 DIGIT ZERO (0) and U+0039 DIGIT NINE (9).
+function isDigit(code) {
+    return code >= 0x0030 && code <= 0x0039;
+}
+
+// hex digit
+// A digit, or a code point between U+0041 LATIN CAPITAL LETTER A (A) and U+0046 LATIN CAPITAL LETTER F (F),
+// or a code point between U+0061 LATIN SMALL LETTER A (a) and U+0066 LATIN SMALL LETTER F (f).
+function isHexDigit(code) {
+    return (
+        isDigit(code) || // 0 .. 9
+        (code >= 0x0041 && code <= 0x0046) || // A .. F
+        (code >= 0x0061 && code <= 0x0066)    // a .. f
+    );
+}
+
+// uppercase letter
+// A code point between U+0041 LATIN CAPITAL LETTER A (A) and U+005A LATIN CAPITAL LETTER Z (Z).
+function isUppercaseLetter(code) {
+    return code >= 0x0041 && code <= 0x005A;
+}
+
+// lowercase letter
+// A code point between U+0061 LATIN SMALL LETTER A (a) and U+007A LATIN SMALL LETTER Z (z).
+function isLowercaseLetter(code) {
+    return code >= 0x0061 && code <= 0x007A;
+}
+
+// letter
+// An uppercase letter or a lowercase letter.
+function isLetter(code) {
+    return isUppercaseLetter(code) || isLowercaseLetter(code);
+}
+
+// non-ASCII code point
+// A code point with a value equal to or greater than U+0080 <control>.
+function isNonAscii(code) {
+    return code >= 0x0080;
+}
+
+// name-start code point
+// A letter, a non-ASCII code point, or U+005F LOW LINE (_).
+function isNameStart(code) {
+    return isLetter(code) || isNonAscii(code) || code === 0x005F;
+}
+
+// name code point
+// A name-start code point, a digit, or U+002D HYPHEN-MINUS (-).
+function isName(code) {
+    return isNameStart(code) || isDigit(code) || code === 0x002D;
+}
+
+// non-printable code point
+// A code point between U+0000 NULL and U+0008 BACKSPACE, or U+000B LINE TABULATION,
+// or a code point between U+000E SHIFT OUT and U+001F INFORMATION SEPARATOR ONE, or U+007F DELETE.
+function isNonPrintable(code) {
+    return (
+        (code >= 0x0000 && code <= 0x0008) ||
+        (code === 0x000B) ||
+        (code >= 0x000E && code <= 0x001F) ||
+        (code === 0x007F)
+    );
+}
+
+// newline
+// U+000A LINE FEED. Note that U+000D CARRIAGE RETURN and U+000C FORM FEED are not included in this definition,
+// as they are converted to U+000A LINE FEED during preprocessing.
+// TODO: we doesn't do a preprocessing, so check a code point for U+000D CARRIAGE RETURN and U+000C FORM FEED
+function isNewline(code) {
+    return code === 0x000A || code === 0x000D || code === 0x000C;
+}
+
+// whitespace
+// A newline, U+0009 CHARACTER TABULATION, or U+0020 SPACE.
+function isWhiteSpace(code) {
+    return isNewline(code) || code === 0x0020 || code === 0x0009;
+}
+
+// § 4.3.8. Check if two code points are a valid escape
+function isValidEscape(first, second) {
+    // If the first code point is not U+005C REVERSE SOLIDUS (\), return false.
+    if (first !== 0x005C) {
+        return false;
+    }
+
+    // Otherwise, if the second code point is a newline or EOF, return false.
+    if (isNewline(second) || second === EOF) {
+        return false;
+    }
+
+    // Otherwise, return true.
+    return true;
+}
+
+// § 4.3.9. Check if three code points would start an identifier
+function isIdentifierStart(first, second, third) {
+    // Look at the first code point:
+
+    // U+002D HYPHEN-MINUS
+    if (first === 0x002D) {
+        // If the second code point is a name-start code point or a U+002D HYPHEN-MINUS,
+        // or the second and third code points are a valid escape, return true. Otherwise, return false.
+        return (
+            isNameStart(second) ||
+            second === 0x002D ||
+            isValidEscape(second, third)
+        );
+    }
+
+    // name-start code point
+    if (isNameStart(first)) {
+        // Return true.
+        return true;
+    }
+
+    // U+005C REVERSE SOLIDUS (\)
+    if (first === 0x005C) {
+        // If the first and second code points are a valid escape, return true. Otherwise, return false.
+        return isValidEscape(first, second);
+    }
+
+    // anything else
+    // Return false.
+    return false;
+}
+
+// § 4.3.10. Check if three code points would start a number
+function isNumberStart(first, second, third) {
+    // Look at the first code point:
+
+    // U+002B PLUS SIGN (+)
+    // U+002D HYPHEN-MINUS (-)
+    if (first === 0x002B || first === 0x002D) {
+        // If the second code point is a digit, return true.
+        if (isDigit(second)) {
+            return 2;
+        }
+
+        // Otherwise, if the second code point is a U+002E FULL STOP (.)
+        // and the third code point is a digit, return true.
+        // Otherwise, return false.
+        return second === 0x002E && isDigit(third) ? 3 : 0;
+    }
+
+    // U+002E FULL STOP (.)
+    if (first === 0x002E) {
+        // If the second code point is a digit, return true. Otherwise, return false.
+        return isDigit(second) ? 2 : 0;
+    }
+
+    // digit
+    if (isDigit(first)) {
+        // Return true.
+        return 1;
+    }
+
+    // anything else
+    // Return false.
+    return 0;
+}
+
+//
+// Misc
+//
+
+// detect BOM (https://en.wikipedia.org/wiki/Byte_order_mark)
+function isBOM(code) {
+    // UTF-16BE
+    if (code === 0xFEFF) {
+        return 1;
+    }
+
+    // UTF-16LE
+    if (code === 0xFFFE) {
+        return 1;
+    }
+
+    return 0;
+}
+
+// Fast code category
+//
+// https://drafts.csswg.org/css-syntax/#tokenizer-definitions
+// > non-ASCII code point
+// >   A code point with a value equal to or greater than U+0080 <control>
+// > name-start code point
+// >   A letter, a non-ASCII code point, or U+005F LOW LINE (_).
+// > name code point
+// >   A name-start code point, a digit, or U+002D HYPHEN-MINUS (-)
+// That means only ASCII code points has a special meaning and we define a maps for 0..127 codes only
+var CATEGORY = new Array(0x80);
+charCodeCategory.Eof = 0x80;
+charCodeCategory.WhiteSpace = 0x82;
+charCodeCategory.Digit = 0x83;
+charCodeCategory.NameStart = 0x84;
+charCodeCategory.NonPrintable = 0x85;
+
+for (var i = 0; i < CATEGORY.length; i++) {
+    switch (true) {
+        case isWhiteSpace(i):
+            CATEGORY[i] = charCodeCategory.WhiteSpace;
+            break;
+
+        case isDigit(i):
+            CATEGORY[i] = charCodeCategory.Digit;
+            break;
+
+        case isNameStart(i):
+            CATEGORY[i] = charCodeCategory.NameStart;
+            break;
+
+        case isNonPrintable(i):
+            CATEGORY[i] = charCodeCategory.NonPrintable;
+            break;
+
+        default:
+            CATEGORY[i] = i || charCodeCategory.Eof;
+    }
+}
+
+function charCodeCategory(code) {
+    return code < 0x80 ? CATEGORY[code] : charCodeCategory.NameStart;
+};
+
+module.exports = {
+    isDigit: isDigit,
+    isHexDigit: isHexDigit,
+    isUppercaseLetter: isUppercaseLetter,
+    isLowercaseLetter: isLowercaseLetter,
+    isLetter: isLetter,
+    isNonAscii: isNonAscii,
+    isNameStart: isNameStart,
+    isName: isName,
+    isNonPrintable: isNonPrintable,
+    isNewline: isNewline,
+    isWhiteSpace: isWhiteSpace,
+    isValidEscape: isValidEscape,
+    isIdentifierStart: isIdentifierStart,
+    isNumberStart: isNumberStart,
+
+    isBOM: isBOM,
+    charCodeCategory: charCodeCategory
+};
diff --git a/node_modules/css-tree/lib/tokenizer/const.js b/node_modules/css-tree/lib/tokenizer/const.js
new file mode 100644
index 0000000..e0f8869
--- /dev/null
+++ b/node_modules/css-tree/lib/tokenizer/const.js
@@ -0,0 +1,40 @@
+// CSS Syntax Module Level 3
+// https://www.w3.org/TR/css-syntax-3/
+var TYPE = {
+    EOF: 0,                 // <EOF-token>
+    Ident: 1,               // <ident-token>
+    Function: 2,            // <function-token>
+    AtKeyword: 3,           // <at-keyword-token>
+    Hash: 4,                // <hash-token>
+    String: 5,              // <string-token>
+    BadString: 6,           // <bad-string-token>
+    Url: 7,                 // <url-token>
+    BadUrl: 8,              // <bad-url-token>
+    Delim: 9,               // <delim-token>
+    Number: 10,             // <number-token>
+    Percentage: 11,         // <percentage-token>
+    Dimension: 12,          // <dimension-token>
+    WhiteSpace: 13,         // <whitespace-token>
+    CDO: 14,                // <CDO-token>
+    CDC: 15,                // <CDC-token>
+    Colon: 16,              // <colon-token>     :
+    Semicolon: 17,          // <semicolon-token> ;
+    Comma: 18,              // <comma-token>     ,
+    LeftSquareBracket: 19,  // <[-token>
+    RightSquareBracket: 20, // <]-token>
+    LeftParenthesis: 21,    // <(-token>
+    RightParenthesis: 22,   // <)-token>
+    LeftCurlyBracket: 23,   // <{-token>
+    RightCurlyBracket: 24,  // <}-token>
+    Comment: 25
+};
+
+var NAME = Object.keys(TYPE).reduce(function(result, key) {
+    result[TYPE[key]] = key;
+    return result;
+}, {});
+
+module.exports = {
+    TYPE: TYPE,
+    NAME: NAME
+};
diff --git a/node_modules/css-tree/lib/tokenizer/index.js b/node_modules/css-tree/lib/tokenizer/index.js
new file mode 100644
index 0000000..dd7ada2
--- /dev/null
+++ b/node_modules/css-tree/lib/tokenizer/index.js
@@ -0,0 +1,591 @@
+var TokenStream = require('../common/TokenStream');
+var adoptBuffer = require('../common/adopt-buffer');
+
+var constants = require('./const');
+var TYPE = constants.TYPE;
+
+var charCodeDefinitions = require('./char-code-definitions');
+var isNewline = charCodeDefinitions.isNewline;
+var isName = charCodeDefinitions.isName;
+var isValidEscape = charCodeDefinitions.isValidEscape;
+var isNumberStart = charCodeDefinitions.isNumberStart;
+var isIdentifierStart = charCodeDefinitions.isIdentifierStart;
+var charCodeCategory = charCodeDefinitions.charCodeCategory;
+var isBOM = charCodeDefinitions.isBOM;
+
+var utils = require('./utils');
+var cmpStr = utils.cmpStr;
+var getNewlineLength = utils.getNewlineLength;
+var findWhiteSpaceEnd = utils.findWhiteSpaceEnd;
+var consumeEscaped = utils.consumeEscaped;
+var consumeName = utils.consumeName;
+var consumeNumber = utils.consumeNumber;
+var consumeBadUrlRemnants = utils.consumeBadUrlRemnants;
+
+var OFFSET_MASK = 0x00FFFFFF;
+var TYPE_SHIFT = 24;
+
+function tokenize(source, stream) {
+    function getCharCode(offset) {
+        return offset < sourceLength ? source.charCodeAt(offset) : 0;
+    }
+
+    // § 4.3.3. Consume a numeric token
+    function consumeNumericToken() {
+        // Consume a number and let number be the result.
+        offset = consumeNumber(source, offset);
+
+        // If the next 3 input code points would start an identifier, then:
+        if (isIdentifierStart(getCharCode(offset), getCharCode(offset + 1), getCharCode(offset + 2))) {
+            // Create a <dimension-token> with the same value and type flag as number, and a unit set initially to the empty string.
+            // Consume a name. Set the <dimension-token>’s unit to the returned value.
+            // Return the <dimension-token>.
+            type = TYPE.Dimension;
+            offset = consumeName(source, offset);
+            return;
+        }
+
+        // Otherwise, if the next input code point is U+0025 PERCENTAGE SIGN (%), consume it.
+        if (getCharCode(offset) === 0x0025) {
+            // Create a <percentage-token> with the same value as number, and return it.
+            type = TYPE.Percentage;
+            offset++;
+            return;
+        }
+
+        // Otherwise, create a <number-token> with the same value and type flag as number, and return it.
+        type = TYPE.Number;
+    }
+
+    // § 4.3.4. Consume an ident-like token
+    function consumeIdentLikeToken() {
+        const nameStartOffset = offset;
+
+        // Consume a name, and let string be the result.
+        offset = consumeName(source, offset);
+
+        // If string’s value is an ASCII case-insensitive match for "url",
+        // and the next input code point is U+0028 LEFT PARENTHESIS ((), consume it.
+        if (cmpStr(source, nameStartOffset, offset, 'url') && getCharCode(offset) === 0x0028) {
+            // While the next two input code points are whitespace, consume the next input code point.
+            offset = findWhiteSpaceEnd(source, offset + 1);
+
+            // If the next one or two input code points are U+0022 QUOTATION MARK ("), U+0027 APOSTROPHE ('),
+            // or whitespace followed by U+0022 QUOTATION MARK (") or U+0027 APOSTROPHE ('),
+            // then create a <function-token> with its value set to string and return it.
+            if (getCharCode(offset) === 0x0022 ||
+                getCharCode(offset) === 0x0027) {
+                type = TYPE.Function;
+                offset = nameStartOffset + 4;
+                return;
+            }
+
+            // Otherwise, consume a url token, and return it.
+            consumeUrlToken();
+            return;
+        }
+
+        // Otherwise, if the next input code point is U+0028 LEFT PARENTHESIS ((), consume it.
+        // Create a <function-token> with its value set to string and return it.
+        if (getCharCode(offset) === 0x0028) {
+            type = TYPE.Function;
+            offset++;
+            return;
+        }
+
+        // Otherwise, create an <ident-token> with its value set to string and return it.
+        type = TYPE.Ident;
+    }
+
+    // § 4.3.5. Consume a string token
+    function consumeStringToken(endingCodePoint) {
+        // This algorithm may be called with an ending code point, which denotes the code point
+        // that ends the string. If an ending code point is not specified,
+        // the current input code point is used.
+        if (!endingCodePoint) {
+            endingCodePoint = getCharCode(offset++);
+        }
+
+        // Initially create a <string-token> with its value set to the empty string.
+        type = TYPE.String;
+
+        // Repeatedly consume the next input code point from the stream:
+        for (; offset < source.length; offset++) {
+            var code = source.charCodeAt(offset);
+
+            switch (charCodeCategory(code)) {
+                // ending code point
+                case endingCodePoint:
+                    // Return the <string-token>.
+                    offset++;
+                    return;
+
+                // EOF
+                case charCodeCategory.Eof:
+                    // This is a parse error. Return the <string-token>.
+                    return;
+
+                // newline
+                case charCodeCategory.WhiteSpace:
+                    if (isNewline(code)) {
+                        // This is a parse error. Reconsume the current input code point,
+                        // create a <bad-string-token>, and return it.
+                        offset += getNewlineLength(source, offset, code);
+                        type = TYPE.BadString;
+                        return;
+                    }
+                    break;
+
+                // U+005C REVERSE SOLIDUS (\)
+                case 0x005C:
+                    // If the next input code point is EOF, do nothing.
+                    if (offset === source.length - 1) {
+                        break;
+                    }
+
+                    var nextCode = getCharCode(offset + 1);
+
+                    // Otherwise, if the next input code point is a newline, consume it.
+                    if (isNewline(nextCode)) {
+                        offset += getNewlineLength(source, offset + 1, nextCode);
+                    } else if (isValidEscape(code, nextCode)) {
+                        // Otherwise, (the stream starts with a valid escape) consume
+                        // an escaped code point and append the returned code point to
+                        // the <string-token>’s value.
+                        offset = consumeEscaped(source, offset) - 1;
+                    }
+                    break;
+
+                // anything else
+                // Append the current input code point to the <string-token>’s value.
+            }
+        }
+    }
+
+    // § 4.3.6. Consume a url token
+    // Note: This algorithm assumes that the initial "url(" has already been consumed.
+    // This algorithm also assumes that it’s being called to consume an "unquoted" value, like url(foo).
+    // A quoted value, like url("foo"), is parsed as a <function-token>. Consume an ident-like token
+    // automatically handles this distinction; this algorithm shouldn’t be called directly otherwise.
+    function consumeUrlToken() {
+        // Initially create a <url-token> with its value set to the empty string.
+        type = TYPE.Url;
+
+        // Consume as much whitespace as possible.
+        offset = findWhiteSpaceEnd(source, offset);
+
+        // Repeatedly consume the next input code point from the stream:
+        for (; offset < source.length; offset++) {
+            var code = source.charCodeAt(offset);
+
+            switch (charCodeCategory(code)) {
+                // U+0029 RIGHT PARENTHESIS ())
+                case 0x0029:
+                    // Return the <url-token>.
+                    offset++;
+                    return;
+
+                // EOF
+                case charCodeCategory.Eof:
+                    // This is a parse error. Return the <url-token>.
+                    return;
+
+                // whitespace
+                case charCodeCategory.WhiteSpace:
+                    // Consume as much whitespace as possible.
+                    offset = findWhiteSpaceEnd(source, offset);
+
+                    // If the next input code point is U+0029 RIGHT PARENTHESIS ()) or EOF,
+                    // consume it and return the <url-token>
+                    // (if EOF was encountered, this is a parse error);
+                    if (getCharCode(offset) === 0x0029 || offset >= source.length) {
+                        if (offset < source.length) {
+                            offset++;
+                        }
+                        return;
+                    }
+
+                    // otherwise, consume the remnants of a bad url, create a <bad-url-token>,
+                    // and return it.
+                    offset = consumeBadUrlRemnants(source, offset);
+                    type = TYPE.BadUrl;
+                    return;
+
+                // U+0022 QUOTATION MARK (")
+                // U+0027 APOSTROPHE (')
+                // U+0028 LEFT PARENTHESIS (()
+                // non-printable code point
+                case 0x0022:
+                case 0x0027:
+                case 0x0028:
+                case charCodeCategory.NonPrintable:
+                    // This is a parse error. Consume the remnants of a bad url,
+                    // create a <bad-url-token>, and return it.
+                    offset = consumeBadUrlRemnants(source, offset);
+                    type = TYPE.BadUrl;
+                    return;
+
+                // U+005C REVERSE SOLIDUS (\)
+                case 0x005C:
+                    // If the stream starts with a valid escape, consume an escaped code point and
+                    // append the returned code point to the <url-token>’s value.
+                    if (isValidEscape(code, getCharCode(offset + 1))) {
+                        offset = consumeEscaped(source, offset) - 1;
+                        break;
+                    }
+
+                    // Otherwise, this is a parse error. Consume the remnants of a bad url,
+                    // create a <bad-url-token>, and return it.
+                    offset = consumeBadUrlRemnants(source, offset);
+                    type = TYPE.BadUrl;
+                    return;
+
+                // anything else
+                // Append the current input code point to the <url-token>’s value.
+            }
+        }
+    }
+
+    if (!stream) {
+        stream = new TokenStream();
+    }
+
+    // ensure source is a string
+    source = String(source || '');
+
+    var sourceLength = source.length;
+    var offsetAndType = adoptBuffer(stream.offsetAndType, sourceLength + 1); // +1 because of eof-token
+    var balance = adoptBuffer(stream.balance, sourceLength + 1);
+    var tokenCount = 0;
+    var start = isBOM(getCharCode(0));
+    var offset = start;
+    var balanceCloseType = 0;
+    var balanceStart = 0;
+    var balancePrev = 0;
+
+    // https://drafts.csswg.org/css-syntax-3/#consume-token
+    // § 4.3.1. Consume a token
+    while (offset < sourceLength) {
+        var code = source.charCodeAt(offset);
+        var type = 0;
+
+        balance[tokenCount] = sourceLength;
+
+        switch (charCodeCategory(code)) {
+            // whitespace
+            case charCodeCategory.WhiteSpace:
+                // Consume as much whitespace as possible. Return a <whitespace-token>.
+                type = TYPE.WhiteSpace;
+                offset = findWhiteSpaceEnd(source, offset + 1);
+                break;
+
+            // U+0022 QUOTATION MARK (")
+            case 0x0022:
+                // Consume a string token and return it.
+                consumeStringToken();
+                break;
+
+            // U+0023 NUMBER SIGN (#)
+            case 0x0023:
+                // If the next input code point is a name code point or the next two input code points are a valid escape, then:
+                if (isName(getCharCode(offset + 1)) || isValidEscape(getCharCode(offset + 1), getCharCode(offset + 2))) {
+                    // Create a <hash-token>.
+                    type = TYPE.Hash;
+
+                    // If the next 3 input code points would start an identifier, set the <hash-token>’s type flag to "id".
+                    // if (isIdentifierStart(getCharCode(offset + 1), getCharCode(offset + 2), getCharCode(offset + 3))) {
+                    //     // TODO: set id flag
+                    // }
+
+                    // Consume a name, and set the <hash-token>’s value to the returned string.
+                    offset = consumeName(source, offset + 1);
+
+                    // Return the <hash-token>.
+                } else {
+                    // Otherwise, return a <delim-token> with its value set to the current input code point.
+                    type = TYPE.Delim;
+                    offset++;
+                }
+
+                break;
+
+            // U+0027 APOSTROPHE (')
+            case 0x0027:
+                // Consume a string token and return it.
+                consumeStringToken();
+                break;
+
+            // U+0028 LEFT PARENTHESIS (()
+            case 0x0028:
+                // Return a <(-token>.
+                type = TYPE.LeftParenthesis;
+                offset++;
+                break;
+
+            // U+0029 RIGHT PARENTHESIS ())
+            case 0x0029:
+                // Return a <)-token>.
+                type = TYPE.RightParenthesis;
+                offset++;
+                break;
+
+            // U+002B PLUS SIGN (+)
+            case 0x002B:
+                // If the input stream starts with a number, ...
+                if (isNumberStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
+                    // ... reconsume the current input code point, consume a numeric token, and return it.
+                    consumeNumericToken();
+                } else {
+                    // Otherwise, return a <delim-token> with its value set to the current input code point.
+                    type = TYPE.Delim;
+                    offset++;
+                }
+                break;
+
+            // U+002C COMMA (,)
+            case 0x002C:
+                // Return a <comma-token>.
+                type = TYPE.Comma;
+                offset++;
+                break;
+
+            // U+002D HYPHEN-MINUS (-)
+            case 0x002D:
+                // If the input stream starts with a number, reconsume the current input code point, consume a numeric token, and return it.
+                if (isNumberStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
+                    consumeNumericToken();
+                } else {
+                    // Otherwise, if the next 2 input code points are U+002D HYPHEN-MINUS U+003E GREATER-THAN SIGN (->), consume them and return a <CDC-token>.
+                    if (getCharCode(offset + 1) === 0x002D &&
+                        getCharCode(offset + 2) === 0x003E) {
+                        type = TYPE.CDC;
+                        offset = offset + 3;
+                    } else {
+                        // Otherwise, if the input stream starts with an identifier, ...
+                        if (isIdentifierStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
+                            // ... reconsume the current input code point, consume an ident-like token, and return it.
+                            consumeIdentLikeToken();
+                        } else {
+                            // Otherwise, return a <delim-token> with its value set to the current input code point.
+                            type = TYPE.Delim;
+                            offset++;
+                        }
+                    }
+                }
+                break;
+
+            // U+002E FULL STOP (.)
+            case 0x002E:
+                // If the input stream starts with a number, ...
+                if (isNumberStart(code, getCharCode(offset + 1), getCharCode(offset + 2))) {
+                    // ... reconsume the current input code point, consume a numeric token, and return it.
+                    consumeNumericToken();
+                } else {
+                    // Otherwise, return a <delim-token> with its value set to the current input code point.
+                    type = TYPE.Delim;
+                    offset++;
+                }
+
+                break;
+
+            // U+002F SOLIDUS (/)
+            case 0x002F:
+                // If the next two input code point are U+002F SOLIDUS (/) followed by a U+002A ASTERISK (*),
+                if (getCharCode(offset + 1) === 0x002A) {
+                    // ... consume them and all following code points up to and including the first U+002A ASTERISK (*)
+                    // followed by a U+002F SOLIDUS (/), or up to an EOF code point.
+                    type = TYPE.Comment;
+                    offset = source.indexOf('*/', offset + 2) + 2;
+                    if (offset === 1) {
+                        offset = source.length;
+                    }
+                } else {
+                    type = TYPE.Delim;
+                    offset++;
+                }
+                break;
+
+            // U+003A COLON (:)
+            case 0x003A:
+                // Return a <colon-token>.
+                type = TYPE.Colon;
+                offset++;
+                break;
+
+            // U+003B SEMICOLON (;)
+            case 0x003B:
+                // Return a <semicolon-token>.
+                type = TYPE.Semicolon;
+                offset++;
+                break;
+
+            // U+003C LESS-THAN SIGN (<)
+            case 0x003C:
+                // If the next 3 input code points are U+0021 EXCLAMATION MARK U+002D HYPHEN-MINUS U+002D HYPHEN-MINUS (!--), ...
+                if (getCharCode(offset + 1) === 0x0021 &&
+                    getCharCode(offset + 2) === 0x002D &&
+                    getCharCode(offset + 3) === 0x002D) {
+                    // ... consume them and return a <CDO-token>.
+                    type = TYPE.CDO;
+                    offset = offset + 4;
+                } else {
+                    // Otherwise, return a <delim-token> with its value set to the current input code point.
+                    type = TYPE.Delim;
+                    offset++;
+                }
+
+                break;
+
+            // U+0040 COMMERCIAL AT (@)
+            case 0x0040:
+                // If the next 3 input code points would start an identifier, ...
+                if (isIdentifierStart(getCharCode(offset + 1), getCharCode(offset + 2), getCharCode(offset + 3))) {
+                    // ... consume a name, create an <at-keyword-token> with its value set to the returned value, and return it.
+                    type = TYPE.AtKeyword;
+                    offset = consumeName(source, offset + 1);
+                } else {
+                    // Otherwise, return a <delim-token> with its value set to the current input code point.
+                    type = TYPE.Delim;
+                    offset++;
+                }
+
+                break;
+
+            // U+005B LEFT SQUARE BRACKET ([)
+            case 0x005B:
+                // Return a <[-token>.
+                type = TYPE.LeftSquareBracket;
+                offset++;
+                break;
+
+            // U+005C REVERSE SOLIDUS (\)
+            case 0x005C:
+                // If the input stream starts with a valid escape, ...
+                if (isValidEscape(code, getCharCode(offset + 1))) {
+                    // ... reconsume the current input code point, consume an ident-like token, and return it.
+                    consumeIdentLikeToken();
+                } else {
+                    // Otherwise, this is a parse error. Return a <delim-token> with its value set to the current input code point.
+                    type = TYPE.Delim;
+                    offset++;
+                }
+                break;
+
+            // U+005D RIGHT SQUARE BRACKET (])
+            case 0x005D:
+                // Return a <]-token>.
+                type = TYPE.RightSquareBracket;
+                offset++;
+                break;
+
+            // U+007B LEFT CURLY BRACKET ({)
+            case 0x007B:
+                // Return a <{-token>.
+                type = TYPE.LeftCurlyBracket;
+                offset++;
+                break;
+
+            // U+007D RIGHT CURLY BRACKET (})
+            case 0x007D:
+                // Return a <}-token>.
+                type = TYPE.RightCurlyBracket;
+                offset++;
+                break;
+
+            // digit
+            case charCodeCategory.Digit:
+                // Reconsume the current input code point, consume a numeric token, and return it.
+                consumeNumericToken();
+                break;
+
+            // name-start code point
+            case charCodeCategory.NameStart:
+                // Reconsume the current input code point, consume an ident-like token, and return it.
+                consumeIdentLikeToken();
+                break;
+
+            // EOF
+            case charCodeCategory.Eof:
+                // Return an <EOF-token>.
+                break;
+
+            // anything else
+            default:
+                // Return a <delim-token> with its value set to the current input code point.
+                type = TYPE.Delim;
+                offset++;
+        }
+
+        switch (type) {
+            case balanceCloseType:
+                balancePrev = balanceStart & OFFSET_MASK;
+                balanceStart = balance[balancePrev];
+                balanceCloseType = balanceStart >> TYPE_SHIFT;
+                balance[tokenCount] = balancePrev;
+                balance[balancePrev++] = tokenCount;
+                for (; balancePrev < tokenCount; balancePrev++) {
+                    if (balance[balancePrev] === sourceLength) {
+                        balance[balancePrev] = tokenCount;
+                    }
+                }
+                break;
+
+            case TYPE.LeftParenthesis:
+            case TYPE.Function:
+                balance[tokenCount] = balanceStart;
+                balanceCloseType = TYPE.RightParenthesis;
+                balanceStart = (balanceCloseType << TYPE_SHIFT) | tokenCount;
+                break;
+
+            case TYPE.LeftSquareBracket:
+                balance[tokenCount] = balanceStart;
+                balanceCloseType = TYPE.RightSquareBracket;
+                balanceStart = (balanceCloseType << TYPE_SHIFT) | tokenCount;
+                break;
+
+            case TYPE.LeftCurlyBracket:
+                balance[tokenCount] = balanceStart;
+                balanceCloseType = TYPE.RightCurlyBracket;
+                balanceStart = (balanceCloseType << TYPE_SHIFT) | tokenCount;
+                break;
+        }
+
+        offsetAndType[tokenCount++] = (type << TYPE_SHIFT) | offset;
+    }
+
+    // finalize buffers
+    offsetAndType[tokenCount] = (TYPE.EOF << TYPE_SHIFT) | offset; // <EOF-token>
+    balance[tokenCount] = sourceLength;
+    balance[sourceLength] = sourceLength; // prevents false positive balance match with any token
+    while (balanceStart !== 0) {
+        balancePrev = balanceStart & OFFSET_MASK;
+        balanceStart = balance[balancePrev];
+        balance[balancePrev] = sourceLength;
+    }
+
+    // update stream
+    stream.source = source;
+    stream.firstCharOffset = start;
+    stream.offsetAndType = offsetAndType;
+    stream.tokenCount = tokenCount;
+    stream.balance = balance;
+    stream.reset();
+    stream.next();
+
+    return stream;
+}
+
+// extend tokenizer with constants
+Object.keys(constants).forEach(function(key) {
+    tokenize[key] = constants[key];
+});
+
+// extend tokenizer with static methods from utils
+Object.keys(charCodeDefinitions).forEach(function(key) {
+    tokenize[key] = charCodeDefinitions[key];
+});
+Object.keys(utils).forEach(function(key) {
+    tokenize[key] = utils[key];
+});
+
+module.exports = tokenize;
diff --git a/node_modules/css-tree/lib/tokenizer/utils.js b/node_modules/css-tree/lib/tokenizer/utils.js
new file mode 100644
index 0000000..f5a38ec
--- /dev/null
+++ b/node_modules/css-tree/lib/tokenizer/utils.js
@@ -0,0 +1,243 @@
+var charCodeDef = require('./char-code-definitions');
+var isDigit = charCodeDef.isDigit;
+var isHexDigit = charCodeDef.isHexDigit;
+var isUppercaseLetter = charCodeDef.isUppercaseLetter;
+var isName = charCodeDef.isName;
+var isWhiteSpace = charCodeDef.isWhiteSpace;
+var isValidEscape = charCodeDef.isValidEscape;
+
+function getCharCode(source, offset) {
+    return offset < source.length ? source.charCodeAt(offset) : 0;
+}
+
+function getNewlineLength(source, offset, code) {
+    if (code === 13 /* \r */ && getCharCode(source, offset + 1) === 10 /* \n */) {
+        return 2;
+    }
+
+    return 1;
+}
+
+function cmpChar(testStr, offset, referenceCode) {
+    var code = testStr.charCodeAt(offset);
+
+    // code.toLowerCase() for A..Z
+    if (isUppercaseLetter(code)) {
+        code = code | 32;
+    }
+
+    return code === referenceCode;
+}
+
+function cmpStr(testStr, start, end, referenceStr) {
+    if (end - start !== referenceStr.length) {
+        return false;
+    }
+
+    if (start < 0 || end > testStr.length) {
+        return false;
+    }
+
+    for (var i = start; i < end; i++) {
+        var testCode = testStr.charCodeAt(i);
+        var referenceCode = referenceStr.charCodeAt(i - start);
+
+        // testCode.toLowerCase() for A..Z
+        if (isUppercaseLetter(testCode)) {
+            testCode = testCode | 32;
+        }
+
+        if (testCode !== referenceCode) {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+function findWhiteSpaceStart(source, offset) {
+    for (; offset >= 0; offset--) {
+        if (!isWhiteSpace(source.charCodeAt(offset))) {
+            break;
+        }
+    }
+
+    return offset + 1;
+}
+
+function findWhiteSpaceEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        if (!isWhiteSpace(source.charCodeAt(offset))) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
+function findDecimalNumberEnd(source, offset) {
+    for (; offset < source.length; offset++) {
+        if (!isDigit(source.charCodeAt(offset))) {
+            break;
+        }
+    }
+
+    return offset;
+}
+
+// § 4.3.7. Consume an escaped code point
+function consumeEscaped(source, offset) {
+    // It assumes that the U+005C REVERSE SOLIDUS (\) has already been consumed and
+    // that the next input code point has already been verified to be part of a valid escape.
+    offset += 2;
+
+    // hex digit
+    if (isHexDigit(getCharCode(source, offset - 1))) {
+        // Consume as many hex digits as possible, but no more than 5.
+        // Note that this means 1-6 hex digits have been consumed in total.
+        for (var maxOffset = Math.min(source.length, offset + 5); offset < maxOffset; offset++) {
+            if (!isHexDigit(getCharCode(source, offset))) {
+                break;
+            }
+        }
+
+        // If the next input code point is whitespace, consume it as well.
+        var code = getCharCode(source, offset);
+        if (isWhiteSpace(code)) {
+            offset += getNewlineLength(source, offset, code);
+        }
+    }
+
+    return offset;
+}
+
+// §4.3.11. Consume a name
+// Note: This algorithm does not do the verification of the first few code points that are necessary
+// to ensure the returned code points would constitute an <ident-token>. If that is the intended use,
+// ensure that the stream starts with an identifier before calling this algorithm.
+function consumeName(source, offset) {
+    // Let result initially be an empty string.
+    // Repeatedly consume the next input code point from the stream:
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        // name code point
+        if (isName(code)) {
+            // Append the code point to result.
+            continue;
+        }
+
+        // the stream starts with a valid escape
+        if (isValidEscape(code, getCharCode(source, offset + 1))) {
+            // Consume an escaped code point. Append the returned code point to result.
+            offset = consumeEscaped(source, offset) - 1;
+            continue;
+        }
+
+        // anything else
+        // Reconsume the current input code point. Return result.
+        break;
+    }
+
+    return offset;
+}
+
+// §4.3.12. Consume a number
+function consumeNumber(source, offset) {
+    var code = source.charCodeAt(offset);
+
+    // 2. If the next input code point is U+002B PLUS SIGN (+) or U+002D HYPHEN-MINUS (-),
+    // consume it and append it to repr.
+    if (code === 0x002B || code === 0x002D) {
+        code = source.charCodeAt(offset += 1);
+    }
+
+    // 3. While the next input code point is a digit, consume it and append it to repr.
+    if (isDigit(code)) {
+        offset = findDecimalNumberEnd(source, offset + 1);
+        code = source.charCodeAt(offset);
+    }
+
+    // 4. If the next 2 input code points are U+002E FULL STOP (.) followed by a digit, then:
+    if (code === 0x002E && isDigit(source.charCodeAt(offset + 1))) {
+        // 4.1 Consume them.
+        // 4.2 Append them to repr.
+        code = source.charCodeAt(offset += 2);
+
+        // 4.3 Set type to "number".
+        // TODO
+
+        // 4.4 While the next input code point is a digit, consume it and append it to repr.
+
+        offset = findDecimalNumberEnd(source, offset);
+    }
+
+    // 5. If the next 2 or 3 input code points are U+0045 LATIN CAPITAL LETTER E (E)
+    // or U+0065 LATIN SMALL LETTER E (e), ... , followed by a digit, then:
+    if (cmpChar(source, offset, 101 /* e */)) {
+        var sign = 0;
+        code = source.charCodeAt(offset + 1);
+
+        // ... optionally followed by U+002D HYPHEN-MINUS (-) or U+002B PLUS SIGN (+) ...
+        if (code === 0x002D || code === 0x002B) {
+            sign = 1;
+            code = source.charCodeAt(offset + 2);
+        }
+
+        // ... followed by a digit
+        if (isDigit(code)) {
+            // 5.1 Consume them.
+            // 5.2 Append them to repr.
+
+            // 5.3 Set type to "number".
+            // TODO
+
+            // 5.4 While the next input code point is a digit, consume it and append it to repr.
+            offset = findDecimalNumberEnd(source, offset + 1 + sign + 1);
+        }
+    }
+
+    return offset;
+}
+
+// § 4.3.14. Consume the remnants of a bad url
+// ... its sole use is to consume enough of the input stream to reach a recovery point
+// where normal tokenizing can resume.
+function consumeBadUrlRemnants(source, offset) {
+    // Repeatedly consume the next input code point from the stream:
+    for (; offset < source.length; offset++) {
+        var code = source.charCodeAt(offset);
+
+        // U+0029 RIGHT PARENTHESIS ())
+        // EOF
+        if (code === 0x0029) {
+            // Return.
+            offset++;
+            break;
+        }
+
+        if (isValidEscape(code, getCharCode(source, offset + 1))) {
+            // Consume an escaped code point.
+            // Note: This allows an escaped right parenthesis ("\)") to be encountered
+            // without ending the <bad-url-token>. This is otherwise identical to
+            // the "anything else" clause.
+            offset = consumeEscaped(source, offset);
+        }
+    }
+
+    return offset;
+}
+
+module.exports = {
+    consumeEscaped: consumeEscaped,
+    consumeName: consumeName,
+    consumeNumber: consumeNumber,
+    consumeBadUrlRemnants: consumeBadUrlRemnants,
+
+    cmpChar: cmpChar,
+    cmpStr: cmpStr,
+
+    getNewlineLength: getNewlineLength,
+    findWhiteSpaceStart: findWhiteSpaceStart,
+    findWhiteSpaceEnd: findWhiteSpaceEnd
+};