Merge CommonElements and BackendHelpers!

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

Index: pkg/compiler/lib/src/js_backend/frequency_namer.dart
diff --git a/pkg/compiler/lib/src/js_backend/frequency_namer.dart b/pkg/compiler/lib/src/js_backend/frequency_namer.dart
index 7ea25d6270a9a1c869d2af4b144b711c73f5e474..9943b4d78e6acd3db34be132b05896e8176af3df 100644
--- a/pkg/compiler/lib/src/js_backend/frequency_namer.dart
+++ b/pkg/compiler/lib/src/js_backend/frequency_namer.dart
@@ -25,9 +25,9 @@ class FrequencyBasedNamer extends Namer
   jsAst.Name get staticsPropertyName =>
       _staticsPropertyName ??= getFreshName(instanceScope, 'static');
 
-  FrequencyBasedNamer(BackendHelpers helpers, NativeData nativeData,
-      ClosedWorld closedWorld, CodegenWorldBuilder codegenWorldBuilder)
-      : super(helpers, nativeData, closedWorld, codegenWorldBuilder) {
+  FrequencyBasedNamer(NativeData nativeData, ClosedWorld closedWorld,
+      CodegenWorldBuilder codegenWorldBuilder)
+      : super(nativeData, closedWorld, codegenWorldBuilder) {
     fieldRegistry = new _FieldNamingRegistry(this);
   }