dart2js: Implement frequency based naming.

pkg/compiler/lib/src/js_emitter/program_builder.dart

 // Copyright (c) 2014, 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_emitter.program_builder;
 
 import 'js_emitter.dart' show computeMixinClass;
 import 'model.dart';
 
 import '../common.dart';
@@ skipping 105 matching lines @@
 
     _markEagerClasses();
 
     List<Holder> holders = _registry.holders.toList(growable: false);
 
     bool needsNativeSupport = _compiler.enqueuer.codegen.nativeEnqueuer
         .hasInstantiatedNativeClasses();
 
     assert(!needsNativeSupport || nativeClasses.isNotEmpty);
 
+    List<js.TokenFinalizer> finalizers = [_task.metadataCollector];
+    if (backend.namer is js.TokenFinalizer) {
+      var namingFinalizer = backend.namer;
+      finalizers.add(namingFinalizer);
+    }
+
     return new Program(
         fragments,
         holders,
         _buildLoadMap(),
         _buildTypeToInterceptorMap(),
         _task.metadataCollector,
+        finalizers,
         needsNativeSupport: needsNativeSupport,
         outputContainsConstantList: _task.outputContainsConstantList,
         hasIsolateSupport: _compiler.hasIsolateSupport);
   }
 
   void _markEagerClasses() {
     _markEagerInterceptorClasses();
   }
 
   /// Builds a map from loadId to outputs-to-load.
@@ skipping 611 matching lines @@
       _registry.registerConstant(outputUnit, constantValue);
       assert(!_constants.containsKey(constantValue));
       js.Name name = namer.constantName(constantValue);
       String constantObject = namer.globalObjectForConstant(constantValue);
       Holder holder = _registry.registerHolder(constantObject);
       Constant constant = new Constant(name, holder, constantValue);
       _constants[constantValue] = constant;
     }
   }
 }