Merge CommonElements and BackendHelpers!

tests/compiler/dart2js/mock_compiler.dart

 // Copyright (c) 2016, 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 mock_compiler;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:compiler/compiler_new.dart' as api;
 import 'package:compiler/src/common/names.dart' show Uris;
 import 'package:compiler/src/constants/expressions.dart';
 import 'package:compiler/src/elements/resolution_types.dart'
     show ResolutionDartType;
 import 'package:compiler/src/diagnostics/diagnostic_listener.dart';
 import 'package:compiler/src/diagnostics/source_span.dart';
 import 'package:compiler/src/diagnostics/spannable.dart';
 import 'package:compiler/src/elements/elements.dart';
 import 'package:compiler/src/elements/visitor.dart';
 import 'package:compiler/src/library_loader.dart' show LoadedLibraries;
-import 'package:compiler/src/js_backend/backend_helpers.dart'
-    show BackendHelpers;
+import 'package:compiler/src/js_backend/backend.dart' show JavaScriptBackend;
 import 'package:compiler/src/js_backend/lookup_map_analysis.dart'
     show LookupMapResolutionAnalysis;
 import 'package:compiler/src/io/source_file.dart';
 import 'package:compiler/src/options.dart' show CompilerOptions;
 import 'package:compiler/src/resolution/members.dart';
 import 'package:compiler/src/resolution/registry.dart';
 import 'package:compiler/src/resolution/scope.dart';
 import 'package:compiler/src/resolution/tree_elements.dart';
 import 'package:compiler/src/resolved_uri_translator.dart';
 import 'package:compiler/src/script.dart';
@@ skipping 75 matching lines @@
                 trustTypeAnnotations: trustTypeAnnotations,
                 trustJSInteropTypeAnnotations: trustJSInteropTypeAnnotations,
                 shownPackageWarnings: const []),
             outputProvider: outputProvider) {
     deferredLoadTask = new MockDeferredLoadTask(this);
 
     registerSource(
         Uris.dart_core, buildLibrarySource(DEFAULT_CORE_LIBRARY, coreSource));
     registerSource(PATCH_CORE, DEFAULT_PATCH_CORE_SOURCE);
 
-    registerSource(BackendHelpers.DART_JS_HELPER,
-        buildLibrarySource(DEFAULT_JS_HELPER_LIBRARY));
-    registerSource(BackendHelpers.DART_FOREIGN_HELPER,
+    registerSource(
+        Uris.dart__js_helper, buildLibrarySource(DEFAULT_JS_HELPER_LIBRARY));
+    registerSource(Uris.dart__foreign_helper,
         buildLibrarySource(DEFAULT_FOREIGN_HELPER_LIBRARY));
-    registerSource(BackendHelpers.DART_INTERCEPTORS,
+    registerSource(Uris.dart__interceptors,
         buildLibrarySource(DEFAULT_INTERCEPTORS_LIBRARY));
-    registerSource(BackendHelpers.DART_ISOLATE_HELPER,
+    registerSource(Uris.dart__isolate_helper,
         buildLibrarySource(DEFAULT_ISOLATE_HELPER_LIBRARY));
     registerSource(Uris.dart_mirrors, DEFAULT_MIRRORS_SOURCE);
-    registerSource(BackendHelpers.DART_JS_MIRRORS, DEFAULT_JS_MIRRORS_SOURCE);
+    registerSource(Uris.dart__js_mirrors, DEFAULT_JS_MIRRORS_SOURCE);
 
     Map<String, String> asyncLibrarySource = <String, String>{};
     asyncLibrarySource.addAll(DEFAULT_ASYNC_LIBRARY);
     if (enableAsyncAwait) {
       asyncLibrarySource.addAll(ASYNC_AWAIT_LIBRARY);
     }
     registerSource(Uris.dart_async, buildLibrarySource(asyncLibrarySource));
     registerSource(LookupMapResolutionAnalysis.PACKAGE_LOOKUP_MAP,
         buildLibrarySource(DEFAULT_LOOKUP_MAP_LIBRARY));
   }
@@ skipping 260 matching lines @@
       trustTypeAnnotations: trustTypeAnnotations,
       enableTypeAssertions: enableTypeAssertions,
       enableUserAssertions: enableUserAssertions,
       expectedErrors: expectedErrors,
       expectedWarnings: expectedWarnings,
       outputProvider: outputProvider);
   compiler.registerSource(uri, code);
   compiler.diagnosticHandler = createHandler(compiler, code);
   return compiler;
 }