dart2js: Remove oldEmitter field in emitter-task.

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

Index: pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
diff --git a/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart b/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
index b3d7bc95454f487095bbfa1a54fea7b428ab02d6..9d700b3480bb1f42801ebb94f2add4b723a93758 100644
--- a/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
+++ b/pkg/compiler/lib/src/js_emitter/code_emitter_task.dart
@@ -18,7 +18,6 @@ class CodeEmitterTask extends CompilerTask {
   final TypeTestRegistry typeTestRegistry;
   NativeEmitter nativeEmitter;
   MetadataCollector metadataCollector;
-  OldEmitter oldEmitter;
   Emitter emitter;
 
   /// Records if a type variable is read dynamically for type tests.
@@ -39,10 +38,9 @@ class CodeEmitterTask extends CompilerTask {
         this.namer = namer,
         this.typeTestRegistry = new TypeTestRegistry(compiler) {
     nativeEmitter = new NativeEmitter(this);
-    oldEmitter = new OldEmitter(compiler, namer, generateSourceMap, this);
     emitter = USE_LAZY_EMITTER
         ? new lazy_js_emitter.Emitter(compiler, namer, nativeEmitter)
-        : oldEmitter;
+        : new OldEmitter(compiler, namer, generateSourceMap, this);
     metadataCollector = new MetadataCollector(compiler, emitter);
   }