Reducing the amount of code we generate in the compiler: We still continue

lib/scoped_css.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/**
+ * This library contains support for scoped CSS that uses the compilation
+ * strategy of WebUI. This will likely become deprecated as we migrate over to
+ * use runtime mechanisms to enforce scoped css rules.
+ */
+library scoped_css;
+
+/**
+ * Maps CSS selectors (class and) to a mangled name and maps x-component name
+ * to [is='x-component'].
+ */
+class ScopedCssMapper {
+  final Map<String, String> _mapping;
+
+  ScopedCssMapper(this._mapping);
+
+  /** Returns mangled name of selector sans . or # character. */
+  String operator [](String selector) => _mapping[selector];
+
+  /** Returns mangled name of selector w/ . or # character. */
+  String getSelector(String selector) {
+    var prefixedName = this[selector];
+    var selectorType = selector[0];
+    if (selectorType == '.' || selectorType == '#') {
+      return '$selectorType${prefixedName}';
+    }
+
+    return prefixedName;
+  }
+}
+
+/** Any CSS selector (class, id or element) defined name to mangled name. */
+Map<String, ScopedCssMapper> _mappers = {};
+
+ScopedCssMapper getScopedCss(String componentName) => _mappers[componentName];
+
+void setScopedCss(String componentName, Map<String, String> mapping) {
+  _mappers.putIfAbsent(componentName, () => new ScopedCssMapper(mapping));
+}