Move namer into javascript backend.

lib/compiler/implementation/js_backend/backend.dart

Index: lib/compiler/implementation/js_backend/backend.dart
diff --git a/lib/compiler/implementation/js_backend/backend.dart b/lib/compiler/implementation/js_backend/backend.dart
index db18924715b65a246ea983d7b30b3b6a8c28ed4c..3040b6426ee74534fef1d74621974b0cd1e94dc0 100644
--- a/lib/compiler/implementation/js_backend/backend.dart
+++ b/lib/compiler/implementation/js_backend/backend.dart
@@ -301,6 +301,8 @@ class JavaScriptBackend extends Backend {
   SsaCodeGeneratorTask generator;
   CodeEmitterTask emitter;
 
+  final Namer namer;
+
   final Map<Element, Map<Element, HType>> fieldInitializers;
   final Map<Element, Map<Element, HType>> fieldConstructorSetters;
   final Map<Element, Map<Element, HType>> fieldSettersType;
@@ -315,13 +317,14 @@ class JavaScriptBackend extends Backend {
   }
 
   JavaScriptBackend(Compiler compiler, bool generateSourceMap)
-      : emitter = new CodeEmitterTask(compiler, generateSourceMap),
-        fieldInitializers = new Map<Element, Map<Element, HType>>(),
+      : fieldInitializers = new Map<Element, Map<Element, HType>>(),
         fieldConstructorSetters = new Map<Element, Map<Element, HType>>(),
         fieldSettersType = new Map<Element, Map<Element, HType>>(),
+        namer = new Namer(compiler),
         returnInfo = new Map<Element, ReturnInfo>(),
         invalidateAfterCodegen = new List<Element>(),
         super(compiler, constantSystem: JAVA_SCRIPT_CONSTANT_SYSTEM) {
+    emitter = new CodeEmitterTask(compiler, namer, generateSourceMap);
     builder = new SsaBuilderTask(this);
     optimizer = new SsaOptimizerTask(this);
     generator = new SsaCodeGeneratorTask(this);