Introduce "CommonElements"

pkg/compiler/lib/src/js_backend/backend_helpers.dart

 // Copyright (c) 2015, 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.
 
 library dart2js.js_backend.helpers;
 
 import '../common.dart';
 import '../common/names.dart' show Identifiers, Uris;
 import '../common/resolution.dart' show Resolution;
 import '../compiler.dart' show Compiler;
@@ skipping 329 matching lines @@
     assert(loadedLibraries.containsLibrary(DART_INTERCEPTORS));
     assert(loadedLibraries.containsLibrary(DART_JS_HELPER));
 
     if (jsInvocationMirrorClass != null) {
       jsInvocationMirrorClass.ensureResolved(resolution);
       invokeOnMethod = jsInvocationMirrorClass.lookupLocalMember(INVOKE_ON);
     }
 
     // [LinkedHashMap] is reexported from dart:collection and can therefore not
     // be loaded from dart:core in [onLibraryScanned].
-    mapLiteralClass = compiler.coreLibrary.find('LinkedHashMap');
-    assert(invariant(compiler.coreLibrary, mapLiteralClass != null,
+    mapLiteralClass = compiler.commonElements.coreLibrary.find('LinkedHashMap');
+    assert(invariant(
+        compiler.commonElements.coreLibrary, mapLiteralClass != null,
         message: "Element 'LinkedHashMap' not found in 'dart:core'."));
 
     // TODO(kasperl): Some tests do not define the special JSArray
     // subclasses, so we check to see if they are defined before
     // trying to resolve them.
     if (jsFixedArrayClass != null) {
       jsFixedArrayClass.ensureResolved(resolution);
     }
     if (jsExtendableArrayClass != null) {
       jsExtendableArrayClass.ensureResolved(resolution);
@@ skipping 252 matching lines @@
     return classElement;
   }
 
   Element get syncStarIterableConstructor {
     ClassElement classElement = syncStarIterable;
     classElement.ensureResolved(resolution);
     return classElement.lookupConstructor("");
   }
 
   Element get syncCompleterConstructor {
-    ClassElement classElement = find(compiler.asyncLibrary, "Completer");
+    ClassElement classElement = find(asyncLibrary, "Completer");
     classElement.ensureResolved(resolution);
     return classElement.lookupConstructor("sync");
   }
 
   Element get asyncStarController {
     ClassElement classElement = findAsyncHelper("_AsyncStarStreamController");
     classElement.ensureResolved(resolution);
     return classElement;
   }
 
   Element get asyncStarControllerConstructor {
     ClassElement classElement = asyncStarController;
     return classElement.lookupConstructor("");
   }
 
   Element get streamIteratorConstructor {
-    ClassElement classElement = find(compiler.asyncLibrary, "StreamIterator");
+    ClassElement classElement = find(asyncLibrary, "StreamIterator");
     classElement.ensureResolved(resolution);
     return classElement.lookupConstructor("");
   }
 
   ClassElement get VoidRuntimeType {
     return findHelper('VoidRuntimeType');
   }
 
   ClassElement get RuntimeType {
     return findHelper('RuntimeType');
@@ skipping 50 matching lines @@
   MethodElement _objectNoSuchMethod;
 
   MethodElement get objectNoSuchMethod {
     if (_objectNoSuchMethod == null) {
       _objectNoSuchMethod =
           coreClasses.objectClass.lookupLocalMember(Identifiers.noSuchMethod_);
     }
     return _objectNoSuchMethod;
   }
 }