Add cssnano

The CSS minifier we currently use (clean-css) is not maintained and
lacks support for new CSS features. CSSNano is a replacement that
supports features we need (primarily container queries).

This CL only adds the relevant dependencies, and does not use it. I will
do that (and remove clean-css) in a follow-up.

Bug: 1399763
Change-Id: I899ecc4482164404dd5ac2fd13f92fb797978e29
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/4092305
Commit-Queue: Jack Franklin <jacktfranklin@chromium.org>
Reviewed-by: Alex Rudenko <alexrudenko@chromium.org>
Commit-Queue: Alex Rudenko <alexrudenko@chromium.org>
Auto-Submit: Jack Franklin <jacktfranklin@chromium.org>
diff --git a/node_modules/lodash.memoize/index.js b/node_modules/lodash.memoize/index.js
new file mode 100644
index 0000000..282ed31
--- /dev/null
+++ b/node_modules/lodash.memoize/index.js
@@ -0,0 +1,676 @@
+/**
+ * lodash (Custom Build) <https://lodash.com/>
+ * Build: `lodash modularize exports="npm" -o ./`
+ * Copyright jQuery Foundation and other contributors <https://jquery.org/>
+ * Released under MIT license <https://lodash.com/license>
+ * Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
+ * Copyright Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+ */
+
+/** Used as the `TypeError` message for "Functions" methods. */
+var FUNC_ERROR_TEXT = 'Expected a function';
+
+/** Used to stand-in for `undefined` hash values. */
+var HASH_UNDEFINED = '__lodash_hash_undefined__';
+
+/** `Object#toString` result references. */
+var funcTag = '[object Function]',
+    genTag = '[object GeneratorFunction]';
+
+/**
+ * Used to match `RegExp`
+ * [syntax characters](http://ecma-international.org/ecma-262/7.0/#sec-patterns).
+ */
+var reRegExpChar = /[\\^$.*+?()[\]{}|]/g;
+
+/** Used to detect host constructors (Safari). */
+var reIsHostCtor = /^\[object .+?Constructor\]$/;
+
+/** Detect free variable `global` from Node.js. */
+var freeGlobal = typeof global == 'object' && global && global.Object === Object && global;
+
+/** Detect free variable `self`. */
+var freeSelf = typeof self == 'object' && self && self.Object === Object && self;
+
+/** Used as a reference to the global object. */
+var root = freeGlobal || freeSelf || Function('return this')();
+
+/**
+ * Gets the value at `key` of `object`.
+ *
+ * @private
+ * @param {Object} [object] The object to query.
+ * @param {string} key The key of the property to get.
+ * @returns {*} Returns the property value.
+ */
+function getValue(object, key) {
+  return object == null ? undefined : object[key];
+}
+
+/**
+ * Checks if `value` is a host object in IE < 9.
+ *
+ * @private
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is a host object, else `false`.
+ */
+function isHostObject(value) {
+  // Many host objects are `Object` objects that can coerce to strings
+  // despite having improperly defined `toString` methods.
+  var result = false;
+  if (value != null && typeof value.toString != 'function') {
+    try {
+      result = !!(value + '');
+    } catch (e) {}
+  }
+  return result;
+}
+
+/** Used for built-in method references. */
+var arrayProto = Array.prototype,
+    funcProto = Function.prototype,
+    objectProto = Object.prototype;
+
+/** Used to detect overreaching core-js shims. */
+var coreJsData = root['__core-js_shared__'];
+
+/** Used to detect methods masquerading as native. */
+var maskSrcKey = (function() {
+  var uid = /[^.]+$/.exec(coreJsData && coreJsData.keys && coreJsData.keys.IE_PROTO || '');
+  return uid ? ('Symbol(src)_1.' + uid) : '';
+}());
+
+/** Used to resolve the decompiled source of functions. */
+var funcToString = funcProto.toString;
+
+/** Used to check objects for own properties. */
+var hasOwnProperty = objectProto.hasOwnProperty;
+
+/**
+ * Used to resolve the
+ * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
+ * of values.
+ */
+var objectToString = objectProto.toString;
+
+/** Used to detect if a method is native. */
+var reIsNative = RegExp('^' +
+  funcToString.call(hasOwnProperty).replace(reRegExpChar, '\\$&')
+  .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$'
+);
+
+/** Built-in value references. */
+var splice = arrayProto.splice;
+
+/* Built-in method references that are verified to be native. */
+var Map = getNative(root, 'Map'),
+    nativeCreate = getNative(Object, 'create');
+
+/**
+ * Creates a hash object.
+ *
+ * @private
+ * @constructor
+ * @param {Array} [entries] The key-value pairs to cache.
+ */
+function Hash(entries) {
+  var index = -1,
+      length = entries ? entries.length : 0;
+
+  this.clear();
+  while (++index < length) {
+    var entry = entries[index];
+    this.set(entry[0], entry[1]);
+  }
+}
+
+/**
+ * Removes all key-value entries from the hash.
+ *
+ * @private
+ * @name clear
+ * @memberOf Hash
+ */
+function hashClear() {
+  this.__data__ = nativeCreate ? nativeCreate(null) : {};
+}
+
+/**
+ * Removes `key` and its value from the hash.
+ *
+ * @private
+ * @name delete
+ * @memberOf Hash
+ * @param {Object} hash The hash to modify.
+ * @param {string} key The key of the value to remove.
+ * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+ */
+function hashDelete(key) {
+  return this.has(key) && delete this.__data__[key];
+}
+
+/**
+ * Gets the hash value for `key`.
+ *
+ * @private
+ * @name get
+ * @memberOf Hash
+ * @param {string} key The key of the value to get.
+ * @returns {*} Returns the entry value.
+ */
+function hashGet(key) {
+  var data = this.__data__;
+  if (nativeCreate) {
+    var result = data[key];
+    return result === HASH_UNDEFINED ? undefined : result;
+  }
+  return hasOwnProperty.call(data, key) ? data[key] : undefined;
+}
+
+/**
+ * Checks if a hash value for `key` exists.
+ *
+ * @private
+ * @name has
+ * @memberOf Hash
+ * @param {string} key The key of the entry to check.
+ * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+ */
+function hashHas(key) {
+  var data = this.__data__;
+  return nativeCreate ? data[key] !== undefined : hasOwnProperty.call(data, key);
+}
+
+/**
+ * Sets the hash `key` to `value`.
+ *
+ * @private
+ * @name set
+ * @memberOf Hash
+ * @param {string} key The key of the value to set.
+ * @param {*} value The value to set.
+ * @returns {Object} Returns the hash instance.
+ */
+function hashSet(key, value) {
+  var data = this.__data__;
+  data[key] = (nativeCreate && value === undefined) ? HASH_UNDEFINED : value;
+  return this;
+}
+
+// Add methods to `Hash`.
+Hash.prototype.clear = hashClear;
+Hash.prototype['delete'] = hashDelete;
+Hash.prototype.get = hashGet;
+Hash.prototype.has = hashHas;
+Hash.prototype.set = hashSet;
+
+/**
+ * Creates an list cache object.
+ *
+ * @private
+ * @constructor
+ * @param {Array} [entries] The key-value pairs to cache.
+ */
+function ListCache(entries) {
+  var index = -1,
+      length = entries ? entries.length : 0;
+
+  this.clear();
+  while (++index < length) {
+    var entry = entries[index];
+    this.set(entry[0], entry[1]);
+  }
+}
+
+/**
+ * Removes all key-value entries from the list cache.
+ *
+ * @private
+ * @name clear
+ * @memberOf ListCache
+ */
+function listCacheClear() {
+  this.__data__ = [];
+}
+
+/**
+ * Removes `key` and its value from the list cache.
+ *
+ * @private
+ * @name delete
+ * @memberOf ListCache
+ * @param {string} key The key of the value to remove.
+ * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+ */
+function listCacheDelete(key) {
+  var data = this.__data__,
+      index = assocIndexOf(data, key);
+
+  if (index < 0) {
+    return false;
+  }
+  var lastIndex = data.length - 1;
+  if (index == lastIndex) {
+    data.pop();
+  } else {
+    splice.call(data, index, 1);
+  }
+  return true;
+}
+
+/**
+ * Gets the list cache value for `key`.
+ *
+ * @private
+ * @name get
+ * @memberOf ListCache
+ * @param {string} key The key of the value to get.
+ * @returns {*} Returns the entry value.
+ */
+function listCacheGet(key) {
+  var data = this.__data__,
+      index = assocIndexOf(data, key);
+
+  return index < 0 ? undefined : data[index][1];
+}
+
+/**
+ * Checks if a list cache value for `key` exists.
+ *
+ * @private
+ * @name has
+ * @memberOf ListCache
+ * @param {string} key The key of the entry to check.
+ * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+ */
+function listCacheHas(key) {
+  return assocIndexOf(this.__data__, key) > -1;
+}
+
+/**
+ * Sets the list cache `key` to `value`.
+ *
+ * @private
+ * @name set
+ * @memberOf ListCache
+ * @param {string} key The key of the value to set.
+ * @param {*} value The value to set.
+ * @returns {Object} Returns the list cache instance.
+ */
+function listCacheSet(key, value) {
+  var data = this.__data__,
+      index = assocIndexOf(data, key);
+
+  if (index < 0) {
+    data.push([key, value]);
+  } else {
+    data[index][1] = value;
+  }
+  return this;
+}
+
+// Add methods to `ListCache`.
+ListCache.prototype.clear = listCacheClear;
+ListCache.prototype['delete'] = listCacheDelete;
+ListCache.prototype.get = listCacheGet;
+ListCache.prototype.has = listCacheHas;
+ListCache.prototype.set = listCacheSet;
+
+/**
+ * Creates a map cache object to store key-value pairs.
+ *
+ * @private
+ * @constructor
+ * @param {Array} [entries] The key-value pairs to cache.
+ */
+function MapCache(entries) {
+  var index = -1,
+      length = entries ? entries.length : 0;
+
+  this.clear();
+  while (++index < length) {
+    var entry = entries[index];
+    this.set(entry[0], entry[1]);
+  }
+}
+
+/**
+ * Removes all key-value entries from the map.
+ *
+ * @private
+ * @name clear
+ * @memberOf MapCache
+ */
+function mapCacheClear() {
+  this.__data__ = {
+    'hash': new Hash,
+    'map': new (Map || ListCache),
+    'string': new Hash
+  };
+}
+
+/**
+ * Removes `key` and its value from the map.
+ *
+ * @private
+ * @name delete
+ * @memberOf MapCache
+ * @param {string} key The key of the value to remove.
+ * @returns {boolean} Returns `true` if the entry was removed, else `false`.
+ */
+function mapCacheDelete(key) {
+  return getMapData(this, key)['delete'](key);
+}
+
+/**
+ * Gets the map value for `key`.
+ *
+ * @private
+ * @name get
+ * @memberOf MapCache
+ * @param {string} key The key of the value to get.
+ * @returns {*} Returns the entry value.
+ */
+function mapCacheGet(key) {
+  return getMapData(this, key).get(key);
+}
+
+/**
+ * Checks if a map value for `key` exists.
+ *
+ * @private
+ * @name has
+ * @memberOf MapCache
+ * @param {string} key The key of the entry to check.
+ * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`.
+ */
+function mapCacheHas(key) {
+  return getMapData(this, key).has(key);
+}
+
+/**
+ * Sets the map `key` to `value`.
+ *
+ * @private
+ * @name set
+ * @memberOf MapCache
+ * @param {string} key The key of the value to set.
+ * @param {*} value The value to set.
+ * @returns {Object} Returns the map cache instance.
+ */
+function mapCacheSet(key, value) {
+  getMapData(this, key).set(key, value);
+  return this;
+}
+
+// Add methods to `MapCache`.
+MapCache.prototype.clear = mapCacheClear;
+MapCache.prototype['delete'] = mapCacheDelete;
+MapCache.prototype.get = mapCacheGet;
+MapCache.prototype.has = mapCacheHas;
+MapCache.prototype.set = mapCacheSet;
+
+/**
+ * Gets the index at which the `key` is found in `array` of key-value pairs.
+ *
+ * @private
+ * @param {Array} array The array to inspect.
+ * @param {*} key The key to search for.
+ * @returns {number} Returns the index of the matched value, else `-1`.
+ */
+function assocIndexOf(array, key) {
+  var length = array.length;
+  while (length--) {
+    if (eq(array[length][0], key)) {
+      return length;
+    }
+  }
+  return -1;
+}
+
+/**
+ * The base implementation of `_.isNative` without bad shim checks.
+ *
+ * @private
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is a native function,
+ *  else `false`.
+ */
+function baseIsNative(value) {
+  if (!isObject(value) || isMasked(value)) {
+    return false;
+  }
+  var pattern = (isFunction(value) || isHostObject(value)) ? reIsNative : reIsHostCtor;
+  return pattern.test(toSource(value));
+}
+
+/**
+ * Gets the data for `map`.
+ *
+ * @private
+ * @param {Object} map The map to query.
+ * @param {string} key The reference key.
+ * @returns {*} Returns the map data.
+ */
+function getMapData(map, key) {
+  var data = map.__data__;
+  return isKeyable(key)
+    ? data[typeof key == 'string' ? 'string' : 'hash']
+    : data.map;
+}
+
+/**
+ * Gets the native function at `key` of `object`.
+ *
+ * @private
+ * @param {Object} object The object to query.
+ * @param {string} key The key of the method to get.
+ * @returns {*} Returns the function if it's native, else `undefined`.
+ */
+function getNative(object, key) {
+  var value = getValue(object, key);
+  return baseIsNative(value) ? value : undefined;
+}
+
+/**
+ * Checks if `value` is suitable for use as unique object key.
+ *
+ * @private
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is suitable, else `false`.
+ */
+function isKeyable(value) {
+  var type = typeof value;
+  return (type == 'string' || type == 'number' || type == 'symbol' || type == 'boolean')
+    ? (value !== '__proto__')
+    : (value === null);
+}
+
+/**
+ * Checks if `func` has its source masked.
+ *
+ * @private
+ * @param {Function} func The function to check.
+ * @returns {boolean} Returns `true` if `func` is masked, else `false`.
+ */
+function isMasked(func) {
+  return !!maskSrcKey && (maskSrcKey in func);
+}
+
+/**
+ * Converts `func` to its source code.
+ *
+ * @private
+ * @param {Function} func The function to process.
+ * @returns {string} Returns the source code.
+ */
+function toSource(func) {
+  if (func != null) {
+    try {
+      return funcToString.call(func);
+    } catch (e) {}
+    try {
+      return (func + '');
+    } catch (e) {}
+  }
+  return '';
+}
+
+/**
+ * Creates a function that memoizes the result of `func`. If `resolver` is
+ * provided, it determines the cache key for storing the result based on the
+ * arguments provided to the memoized function. By default, the first argument
+ * provided to the memoized function is used as the map cache key. The `func`
+ * is invoked with the `this` binding of the memoized function.
+ *
+ * **Note:** The cache is exposed as the `cache` property on the memoized
+ * function. Its creation may be customized by replacing the `_.memoize.Cache`
+ * constructor with one whose instances implement the
+ * [`Map`](http://ecma-international.org/ecma-262/7.0/#sec-properties-of-the-map-prototype-object)
+ * method interface of `delete`, `get`, `has`, and `set`.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Function
+ * @param {Function} func The function to have its output memoized.
+ * @param {Function} [resolver] The function to resolve the cache key.
+ * @returns {Function} Returns the new memoized function.
+ * @example
+ *
+ * var object = { 'a': 1, 'b': 2 };
+ * var other = { 'c': 3, 'd': 4 };
+ *
+ * var values = _.memoize(_.values);
+ * values(object);
+ * // => [1, 2]
+ *
+ * values(other);
+ * // => [3, 4]
+ *
+ * object.a = 2;
+ * values(object);
+ * // => [1, 2]
+ *
+ * // Modify the result cache.
+ * values.cache.set(object, ['a', 'b']);
+ * values(object);
+ * // => ['a', 'b']
+ *
+ * // Replace `_.memoize.Cache`.
+ * _.memoize.Cache = WeakMap;
+ */
+function memoize(func, resolver) {
+  if (typeof func != 'function' || (resolver && typeof resolver != 'function')) {
+    throw new TypeError(FUNC_ERROR_TEXT);
+  }
+  var memoized = function() {
+    var args = arguments,
+        key = resolver ? resolver.apply(this, args) : args[0],
+        cache = memoized.cache;
+
+    if (cache.has(key)) {
+      return cache.get(key);
+    }
+    var result = func.apply(this, args);
+    memoized.cache = cache.set(key, result);
+    return result;
+  };
+  memoized.cache = new (memoize.Cache || MapCache);
+  return memoized;
+}
+
+// Assign cache to `_.memoize`.
+memoize.Cache = MapCache;
+
+/**
+ * Performs a
+ * [`SameValueZero`](http://ecma-international.org/ecma-262/7.0/#sec-samevaluezero)
+ * comparison between two values to determine if they are equivalent.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.0.0
+ * @category Lang
+ * @param {*} value The value to compare.
+ * @param {*} other The other value to compare.
+ * @returns {boolean} Returns `true` if the values are equivalent, else `false`.
+ * @example
+ *
+ * var object = { 'a': 1 };
+ * var other = { 'a': 1 };
+ *
+ * _.eq(object, object);
+ * // => true
+ *
+ * _.eq(object, other);
+ * // => false
+ *
+ * _.eq('a', 'a');
+ * // => true
+ *
+ * _.eq('a', Object('a'));
+ * // => false
+ *
+ * _.eq(NaN, NaN);
+ * // => true
+ */
+function eq(value, other) {
+  return value === other || (value !== value && other !== other);
+}
+
+/**
+ * Checks if `value` is classified as a `Function` object.
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is a function, else `false`.
+ * @example
+ *
+ * _.isFunction(_);
+ * // => true
+ *
+ * _.isFunction(/abc/);
+ * // => false
+ */
+function isFunction(value) {
+  // The use of `Object#toString` avoids issues with the `typeof` operator
+  // in Safari 8-9 which returns 'object' for typed array and other constructors.
+  var tag = isObject(value) ? objectToString.call(value) : '';
+  return tag == funcTag || tag == genTag;
+}
+
+/**
+ * Checks if `value` is the
+ * [language type](http://www.ecma-international.org/ecma-262/7.0/#sec-ecmascript-language-types)
+ * of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
+ *
+ * @static
+ * @memberOf _
+ * @since 0.1.0
+ * @category Lang
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `value` is an object, else `false`.
+ * @example
+ *
+ * _.isObject({});
+ * // => true
+ *
+ * _.isObject([1, 2, 3]);
+ * // => true
+ *
+ * _.isObject(_.noop);
+ * // => true
+ *
+ * _.isObject(null);
+ * // => false
+ */
+function isObject(value) {
+  var type = typeof value;
+  return !!value && (type == 'object' || type == 'function');
+}
+
+module.exports = memoize;