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/lexer/generic.js b/node_modules/css-tree/lib/lexer/generic.js
new file mode 100644
index 0000000..c5b733a
--- /dev/null
+++ b/node_modules/css-tree/lib/lexer/generic.js
@@ -0,0 +1,585 @@
+var tokenizer = require('../tokenizer');
+var isIdentifierStart = tokenizer.isIdentifierStart;
+var isHexDigit = tokenizer.isHexDigit;
+var isDigit = tokenizer.isDigit;
+var cmpStr = tokenizer.cmpStr;
+var consumeNumber = tokenizer.consumeNumber;
+var TYPE = tokenizer.TYPE;
+var anPlusB = require('./generic-an-plus-b');
+var urange = require('./generic-urange');
+
+var cssWideKeywords = ['unset', 'initial', 'inherit'];
+var calcFunctionNames = ['calc(', '-moz-calc(', '-webkit-calc('];
+
+// https://www.w3.org/TR/css-values-3/#lengths
+var LENGTH = {
+    // absolute length units
+    'px': true,
+    'mm': true,
+    'cm': true,
+    'in': true,
+    'pt': true,
+    'pc': true,
+    'q': true,
+
+    // relative length units
+    'em': true,
+    'ex': true,
+    'ch': true,
+    'rem': true,
+
+    // viewport-percentage lengths
+    'vh': true,
+    'vw': true,
+    'vmin': true,
+    'vmax': true,
+    'vm': true
+};
+
+var ANGLE = {
+    'deg': true,
+    'grad': true,
+    'rad': true,
+    'turn': true
+};
+
+var TIME = {
+    's': true,
+    'ms': true
+};
+
+var FREQUENCY = {
+    'hz': true,
+    'khz': true
+};
+
+// https://www.w3.org/TR/css-values-3/#resolution (https://drafts.csswg.org/css-values/#resolution)
+var RESOLUTION = {
+    'dpi': true,
+    'dpcm': true,
+    'dppx': true,
+    'x': true      // https://github.com/w3c/csswg-drafts/issues/461
+};
+
+// https://drafts.csswg.org/css-grid/#fr-unit
+var FLEX = {
+    'fr': true
+};
+
+// https://www.w3.org/TR/css3-speech/#mixing-props-voice-volume
+var DECIBEL = {
+    'db': true
+};
+
+// https://www.w3.org/TR/css3-speech/#voice-props-voice-pitch
+var SEMITONES = {
+    'st': true
+};
+
+// safe char code getter
+function charCode(str, index) {
+    return index < str.length ? str.charCodeAt(index) : 0;
+}
+
+function eqStr(actual, expected) {
+    return cmpStr(actual, 0, actual.length, expected);
+}
+
+function eqStrAny(actual, expected) {
+    for (var i = 0; i < expected.length; i++) {
+        if (eqStr(actual, expected[i])) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+// IE postfix hack, i.e. 123\0 or 123px\9
+function isPostfixIeHack(str, offset) {
+    if (offset !== str.length - 2) {
+        return false;
+    }
+
+    return (
+        str.charCodeAt(offset) === 0x005C &&  // U+005C REVERSE SOLIDUS (\)
+        isDigit(str.charCodeAt(offset + 1))
+    );
+}
+
+function outOfRange(opts, value, numEnd) {
+    if (opts && opts.type === 'Range') {
+        var num = Number(
+            numEnd !== undefined && numEnd !== value.length
+                ? value.substr(0, numEnd)
+                : value
+        );
+
+        if (isNaN(num)) {
+            return true;
+        }
+
+        if (opts.min !== null && num < opts.min) {
+            return true;
+        }
+
+        if (opts.max !== null && num > opts.max) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+function consumeFunction(token, getNextToken) {
+    var startIdx = token.index;
+    var length = 0;
+
+    // balanced token consuming
+    do {
+        length++;
+
+        if (token.balance <= startIdx) {
+            break;
+        }
+    } while (token = getNextToken(length));
+
+    return length;
+}
+
+// TODO: implement
+// can be used wherever <length>, <frequency>, <angle>, <time>, <percentage>, <number>, or <integer> values are allowed
+// https://drafts.csswg.org/css-values/#calc-notation
+function calc(next) {
+    return function(token, getNextToken, opts) {
+        if (token === null) {
+            return 0;
+        }
+
+        if (token.type === TYPE.Function && eqStrAny(token.value, calcFunctionNames)) {
+            return consumeFunction(token, getNextToken);
+        }
+
+        return next(token, getNextToken, opts);
+    };
+}
+
+function tokenType(expectedTokenType) {
+    return function(token) {
+        if (token === null || token.type !== expectedTokenType) {
+            return 0;
+        }
+
+        return 1;
+    };
+}
+
+function func(name) {
+    name = name + '(';
+
+    return function(token, getNextToken) {
+        if (token !== null && eqStr(token.value, name)) {
+            return consumeFunction(token, getNextToken);
+        }
+
+        return 0;
+    };
+}
+
+// =========================
+// Complex types
+//
+
+// https://drafts.csswg.org/css-values-4/#custom-idents
+// 4.2. Author-defined Identifiers: the <custom-ident> type
+// Some properties accept arbitrary author-defined identifiers as a component value.
+// This generic data type is denoted by <custom-ident>, and represents any valid CSS identifier
+// that would not be misinterpreted as a pre-defined keyword in that property’s value definition.
+//
+// See also: https://developer.mozilla.org/en-US/docs/Web/CSS/custom-ident
+function customIdent(token) {
+    if (token === null || token.type !== TYPE.Ident) {
+        return 0;
+    }
+
+    var name = token.value.toLowerCase();
+
+    // The CSS-wide keywords are not valid <custom-ident>s
+    if (eqStrAny(name, cssWideKeywords)) {
+        return 0;
+    }
+
+    // The default keyword is reserved and is also not a valid <custom-ident>
+    if (eqStr(name, 'default')) {
+        return 0;
+    }
+
+    // TODO: ignore property specific keywords (as described https://developer.mozilla.org/en-US/docs/Web/CSS/custom-ident)
+    // Specifications using <custom-ident> must specify clearly what other keywords
+    // are excluded from <custom-ident>, if any—for example by saying that any pre-defined keywords
+    // in that property’s value definition are excluded. Excluded keywords are excluded
+    // in all ASCII case permutations.
+
+    return 1;
+}
+
+// https://drafts.csswg.org/css-variables/#typedef-custom-property-name
+// A custom property is any property whose name starts with two dashes (U+002D HYPHEN-MINUS), like --foo.
+// The <custom-property-name> production corresponds to this: it’s defined as any valid identifier
+// that starts with two dashes, except -- itself, which is reserved for future use by CSS.
+// NOTE: Current implementation treat `--` as a valid name since most (all?) major browsers treat it as valid.
+function customPropertyName(token) {
+    // ... defined as any valid identifier
+    if (token === null || token.type !== TYPE.Ident) {
+        return 0;
+    }
+
+    // ... that starts with two dashes (U+002D HYPHEN-MINUS)
+    if (charCode(token.value, 0) !== 0x002D || charCode(token.value, 1) !== 0x002D) {
+        return 0;
+    }
+
+    return 1;
+}
+
+// https://drafts.csswg.org/css-color-4/#hex-notation
+// The syntax of a <hex-color> is a <hash-token> token whose value consists of 3, 4, 6, or 8 hexadecimal digits.
+// In other words, a hex color is written as a hash character, "#", followed by some number of digits 0-9 or
+// letters a-f (the case of the letters doesn’t matter - #00ff00 is identical to #00FF00).
+function hexColor(token) {
+    if (token === null || token.type !== TYPE.Hash) {
+        return 0;
+    }
+
+    var length = token.value.length;
+
+    // valid values (length): #rgb (4), #rgba (5), #rrggbb (7), #rrggbbaa (9)
+    if (length !== 4 && length !== 5 && length !== 7 && length !== 9) {
+        return 0;
+    }
+
+    for (var i = 1; i < length; i++) {
+        if (!isHexDigit(token.value.charCodeAt(i))) {
+            return 0;
+        }
+    }
+
+    return 1;
+}
+
+function idSelector(token) {
+    if (token === null || token.type !== TYPE.Hash) {
+        return 0;
+    }
+
+    if (!isIdentifierStart(charCode(token.value, 1), charCode(token.value, 2), charCode(token.value, 3))) {
+        return 0;
+    }
+
+    return 1;
+}
+
+// https://drafts.csswg.org/css-syntax/#any-value
+// It represents the entirety of what a valid declaration can have as its value.
+function declarationValue(token, getNextToken) {
+    if (!token) {
+        return 0;
+    }
+
+    var length = 0;
+    var level = 0;
+    var startIdx = token.index;
+
+    // The <declaration-value> production matches any sequence of one or more tokens,
+    // so long as the sequence ...
+    scan:
+    do {
+        switch (token.type) {
+            // ... does not contain <bad-string-token>, <bad-url-token>,
+            case TYPE.BadString:
+            case TYPE.BadUrl:
+                break scan;
+
+            // ... unmatched <)-token>, <]-token>, or <}-token>,
+            case TYPE.RightCurlyBracket:
+            case TYPE.RightParenthesis:
+            case TYPE.RightSquareBracket:
+                if (token.balance > token.index || token.balance < startIdx) {
+                    break scan;
+                }
+
+                level--;
+                break;
+
+            // ... or top-level <semicolon-token> tokens
+            case TYPE.Semicolon:
+                if (level === 0) {
+                    break scan;
+                }
+
+                break;
+
+            // ... or <delim-token> tokens with a value of "!"
+            case TYPE.Delim:
+                if (token.value === '!' && level === 0) {
+                    break scan;
+                }
+
+                break;
+
+            case TYPE.Function:
+            case TYPE.LeftParenthesis:
+            case TYPE.LeftSquareBracket:
+            case TYPE.LeftCurlyBracket:
+                level++;
+                break;
+        }
+
+        length++;
+
+        // until balance closing
+        if (token.balance <= startIdx) {
+            break;
+        }
+    } while (token = getNextToken(length));
+
+    return length;
+}
+
+// https://drafts.csswg.org/css-syntax/#any-value
+// The <any-value> production is identical to <declaration-value>, but also
+// allows top-level <semicolon-token> tokens and <delim-token> tokens
+// with a value of "!". It represents the entirety of what valid CSS can be in any context.
+function anyValue(token, getNextToken) {
+    if (!token) {
+        return 0;
+    }
+
+    var startIdx = token.index;
+    var length = 0;
+
+    // The <any-value> production matches any sequence of one or more tokens,
+    // so long as the sequence ...
+    scan:
+    do {
+        switch (token.type) {
+            // ... does not contain <bad-string-token>, <bad-url-token>,
+            case TYPE.BadString:
+            case TYPE.BadUrl:
+                break scan;
+
+            // ... unmatched <)-token>, <]-token>, or <}-token>,
+            case TYPE.RightCurlyBracket:
+            case TYPE.RightParenthesis:
+            case TYPE.RightSquareBracket:
+                if (token.balance > token.index || token.balance < startIdx) {
+                    break scan;
+                }
+
+                break;
+        }
+
+        length++;
+
+        // until balance closing
+        if (token.balance <= startIdx) {
+            break;
+        }
+    } while (token = getNextToken(length));
+
+    return length;
+}
+
+// =========================
+// Dimensions
+//
+
+function dimension(type) {
+    return function(token, getNextToken, opts) {
+        if (token === null || token.type !== TYPE.Dimension) {
+            return 0;
+        }
+
+        var numberEnd = consumeNumber(token.value, 0);
+
+        // check unit
+        if (type !== null) {
+            // check for IE postfix hack, i.e. 123px\0 or 123px\9
+            var reverseSolidusOffset = token.value.indexOf('\\', numberEnd);
+            var unit = reverseSolidusOffset === -1 || !isPostfixIeHack(token.value, reverseSolidusOffset)
+                ? token.value.substr(numberEnd)
+                : token.value.substring(numberEnd, reverseSolidusOffset);
+
+            if (type.hasOwnProperty(unit.toLowerCase()) === false) {
+                return 0;
+            }
+        }
+
+        // check range if specified
+        if (outOfRange(opts, token.value, numberEnd)) {
+            return 0;
+        }
+
+        return 1;
+    };
+}
+
+// =========================
+// Percentage
+//
+
+// §5.5. Percentages: the <percentage> type
+// https://drafts.csswg.org/css-values-4/#percentages
+function percentage(token, getNextToken, opts) {
+    // ... corresponds to the <percentage-token> production
+    if (token === null || token.type !== TYPE.Percentage) {
+        return 0;
+    }
+
+    // check range if specified
+    if (outOfRange(opts, token.value, token.value.length - 1)) {
+        return 0;
+    }
+
+    return 1;
+}
+
+// =========================
+// Numeric
+//
+
+// https://drafts.csswg.org/css-values-4/#numbers
+// The value <zero> represents a literal number with the value 0. Expressions that merely
+// evaluate to a <number> with the value 0 (for example, calc(0)) do not match <zero>;
+// only literal <number-token>s do.
+function zero(next) {
+    if (typeof next !== 'function') {
+        next = function() {
+            return 0;
+        };
+    }
+
+    return function(token, getNextToken, opts) {
+        if (token !== null && token.type === TYPE.Number) {
+            if (Number(token.value) === 0) {
+                return 1;
+            }
+        }
+
+        return next(token, getNextToken, opts);
+    };
+}
+
+// § 5.3. Real Numbers: the <number> type
+// https://drafts.csswg.org/css-values-4/#numbers
+// Number values are denoted by <number>, and represent real numbers, possibly with a fractional component.
+// ... It corresponds to the <number-token> production
+function number(token, getNextToken, opts) {
+    if (token === null) {
+        return 0;
+    }
+
+    var numberEnd = consumeNumber(token.value, 0);
+    var isNumber = numberEnd === token.value.length;
+    if (!isNumber && !isPostfixIeHack(token.value, numberEnd)) {
+        return 0;
+    }
+
+    // check range if specified
+    if (outOfRange(opts, token.value, numberEnd)) {
+        return 0;
+    }
+
+    return 1;
+}
+
+// §5.2. Integers: the <integer> type
+// https://drafts.csswg.org/css-values-4/#integers
+function integer(token, getNextToken, opts) {
+    // ... corresponds to a subset of the <number-token> production
+    if (token === null || token.type !== TYPE.Number) {
+        return 0;
+    }
+
+    // The first digit of an integer may be immediately preceded by `-` or `+` to indicate the integer’s sign.
+    var i = token.value.charCodeAt(0) === 0x002B ||       // U+002B PLUS SIGN (+)
+            token.value.charCodeAt(0) === 0x002D ? 1 : 0; // U+002D HYPHEN-MINUS (-)
+
+    // When written literally, an integer is one or more decimal digits 0 through 9 ...
+    for (; i < token.value.length; i++) {
+        if (!isDigit(token.value.charCodeAt(i))) {
+            return 0;
+        }
+    }
+
+    // check range if specified
+    if (outOfRange(opts, token.value, i)) {
+        return 0;
+    }
+
+    return 1;
+}
+
+module.exports = {
+    // token types
+    'ident-token': tokenType(TYPE.Ident),
+    'function-token': tokenType(TYPE.Function),
+    'at-keyword-token': tokenType(TYPE.AtKeyword),
+    'hash-token': tokenType(TYPE.Hash),
+    'string-token': tokenType(TYPE.String),
+    'bad-string-token': tokenType(TYPE.BadString),
+    'url-token': tokenType(TYPE.Url),
+    'bad-url-token': tokenType(TYPE.BadUrl),
+    'delim-token': tokenType(TYPE.Delim),
+    'number-token': tokenType(TYPE.Number),
+    'percentage-token': tokenType(TYPE.Percentage),
+    'dimension-token': tokenType(TYPE.Dimension),
+    'whitespace-token': tokenType(TYPE.WhiteSpace),
+    'CDO-token': tokenType(TYPE.CDO),
+    'CDC-token': tokenType(TYPE.CDC),
+    'colon-token': tokenType(TYPE.Colon),
+    'semicolon-token': tokenType(TYPE.Semicolon),
+    'comma-token': tokenType(TYPE.Comma),
+    '[-token': tokenType(TYPE.LeftSquareBracket),
+    ']-token': tokenType(TYPE.RightSquareBracket),
+    '(-token': tokenType(TYPE.LeftParenthesis),
+    ')-token': tokenType(TYPE.RightParenthesis),
+    '{-token': tokenType(TYPE.LeftCurlyBracket),
+    '}-token': tokenType(TYPE.RightCurlyBracket),
+
+    // token type aliases
+    'string': tokenType(TYPE.String),
+    'ident': tokenType(TYPE.Ident),
+
+    // complex types
+    'custom-ident': customIdent,
+    'custom-property-name': customPropertyName,
+    'hex-color': hexColor,
+    'id-selector': idSelector, // element( <id-selector> )
+    'an-plus-b': anPlusB,
+    'urange': urange,
+    'declaration-value': declarationValue,
+    'any-value': anyValue,
+
+    // dimensions
+    'dimension': calc(dimension(null)),
+    'angle': calc(dimension(ANGLE)),
+    'decibel': calc(dimension(DECIBEL)),
+    'frequency': calc(dimension(FREQUENCY)),
+    'flex': calc(dimension(FLEX)),
+    'length': calc(zero(dimension(LENGTH))),
+    'resolution': calc(dimension(RESOLUTION)),
+    'semitones': calc(dimension(SEMITONES)),
+    'time': calc(dimension(TIME)),
+
+    // percentage
+    'percentage': calc(percentage),
+
+    // numeric
+    'zero': zero(),
+    'number': calc(number),
+    'integer': calc(integer),
+
+    // old IE stuff
+    '-ms-legacy-expression': func('expression')
+};