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/structure.js b/node_modules/css-tree/lib/lexer/structure.js
new file mode 100644
index 0000000..e1239dd
--- /dev/null
+++ b/node_modules/css-tree/lib/lexer/structure.js
@@ -0,0 +1,163 @@
+var List = require('../common/List');
+var hasOwnProperty = Object.prototype.hasOwnProperty;
+
+function isValidNumber(value) {
+    // Number.isInteger(value) && value >= 0
+    return (
+        typeof value === 'number' &&
+        isFinite(value) &&
+        Math.floor(value) === value &&
+        value >= 0
+    );
+}
+
+function isValidLocation(loc) {
+    return (
+        Boolean(loc) &&
+        isValidNumber(loc.offset) &&
+        isValidNumber(loc.line) &&
+        isValidNumber(loc.column)
+    );
+}
+
+function createNodeStructureChecker(type, fields) {
+    return function checkNode(node, warn) {
+        if (!node || node.constructor !== Object) {
+            return warn(node, 'Type of node should be an Object');
+        }
+
+        for (var key in node) {
+            var valid = true;
+
+            if (hasOwnProperty.call(node, key) === false) {
+                continue;
+            }
+
+            if (key === 'type') {
+                if (node.type !== type) {
+                    warn(node, 'Wrong node type `' + node.type + '`, expected `' + type + '`');
+                }
+            } else if (key === 'loc') {
+                if (node.loc === null) {
+                    continue;
+                } else if (node.loc && node.loc.constructor === Object) {
+                    if (typeof node.loc.source !== 'string') {
+                        key += '.source';
+                    } else if (!isValidLocation(node.loc.start)) {
+                        key += '.start';
+                    } else if (!isValidLocation(node.loc.end)) {
+                        key += '.end';
+                    } else {
+                        continue;
+                    }
+                }
+
+                valid = false;
+            } else if (fields.hasOwnProperty(key)) {
+                for (var i = 0, valid = false; !valid && i < fields[key].length; i++) {
+                    var fieldType = fields[key][i];
+
+                    switch (fieldType) {
+                        case String:
+                            valid = typeof node[key] === 'string';
+                            break;
+
+                        case Boolean:
+                            valid = typeof node[key] === 'boolean';
+                            break;
+
+                        case null:
+                            valid = node[key] === null;
+                            break;
+
+                        default:
+                            if (typeof fieldType === 'string') {
+                                valid = node[key] && node[key].type === fieldType;
+                            } else if (Array.isArray(fieldType)) {
+                                valid = node[key] instanceof List;
+                            }
+                    }
+                }
+            } else {
+                warn(node, 'Unknown field `' + key + '` for ' + type + ' node type');
+            }
+
+            if (!valid) {
+                warn(node, 'Bad value for `' + type + '.' + key + '`');
+            }
+        }
+
+        for (var key in fields) {
+            if (hasOwnProperty.call(fields, key) &&
+                hasOwnProperty.call(node, key) === false) {
+                warn(node, 'Field `' + type + '.' + key + '` is missed');
+            }
+        }
+    };
+}
+
+function processStructure(name, nodeType) {
+    var structure = nodeType.structure;
+    var fields = {
+        type: String,
+        loc: true
+    };
+    var docs = {
+        type: '"' + name + '"'
+    };
+
+    for (var key in structure) {
+        if (hasOwnProperty.call(structure, key) === false) {
+            continue;
+        }
+
+        var docsTypes = [];
+        var fieldTypes = fields[key] = Array.isArray(structure[key])
+            ? structure[key].slice()
+            : [structure[key]];
+
+        for (var i = 0; i < fieldTypes.length; i++) {
+            var fieldType = fieldTypes[i];
+            if (fieldType === String || fieldType === Boolean) {
+                docsTypes.push(fieldType.name);
+            } else if (fieldType === null) {
+                docsTypes.push('null');
+            } else if (typeof fieldType === 'string') {
+                docsTypes.push('<' + fieldType + '>');
+            } else if (Array.isArray(fieldType)) {
+                docsTypes.push('List'); // TODO: use type enum
+            } else {
+                throw new Error('Wrong value `' + fieldType + '` in `' + name + '.' + key + '` structure definition');
+            }
+        }
+
+        docs[key] = docsTypes.join(' | ');
+    }
+
+    return {
+        docs: docs,
+        check: createNodeStructureChecker(name, fields)
+    };
+}
+
+module.exports = {
+    getStructureFromConfig: function(config) {
+        var structure = {};
+
+        if (config.node) {
+            for (var name in config.node) {
+                if (hasOwnProperty.call(config.node, name)) {
+                    var nodeType = config.node[name];
+
+                    if (nodeType.structure) {
+                        structure[name] = processStructure(name, nodeType);
+                    } else {
+                        throw new Error('Missed `structure` field in `' + name + '` node type definition');
+                    }
+                }
+            }
+        }
+
+        return structure;
+    }
+};