Start compiler refactoring to support more than a single backend.

lib/compiler/implementation/emitter.dart

Index: lib/compiler/implementation/emitter.dart
diff --git a/lib/compiler/implementation/emitter.dart b/lib/compiler/implementation/emitter.dart
index 09ceef28793163e69cbc3b81dceb9fad1b728bda..04439d41d4d33fa58aaab9a54313dfc28b3a3494 100644
--- a/lib/compiler/implementation/emitter.dart
+++ b/lib/compiler/implementation/emitter.dart
@@ -25,7 +25,7 @@ class CodeEmitterTask extends CompilerTask {
   bool needsDefineClass = false;
   bool needsClosureClass = false;
   final Namer namer;
-  final NativeEmitter nativeEmitter;
+  NativeEmitter nativeEmitter;
   StringBuffer boundClosureBuffer;
   StringBuffer mainBuffer;
   /** Shorter access to [isolatePropertiesName]. Both here in the code, as
@@ -34,10 +34,11 @@ class CodeEmitterTask extends CompilerTask {
 
   CodeEmitterTask(Compiler compiler)
       : namer = compiler.namer,
-        nativeEmitter = new NativeEmitter(compiler),
         boundClosureBuffer = new StringBuffer(),
         mainBuffer = new StringBuffer(),
-        super(compiler);
+        super(compiler) {
+    nativeEmitter = new NativeEmitter(this);
+  }
 
   String get name() => 'CodeEmitter';
 
@@ -770,13 +771,11 @@ function() {
     if (member.kind == ElementKind.GETTER || member.kind == ElementKind.FIELD) {
       Set<Selector> selectors = compiler.universe.invokedNames[member.name];
       if (selectors !== null && !selectors.isEmpty()) {
-        compiler.emitter.emitCallStubForGetter(member, selectors,
-                                               defineInstanceMember);
+        emitCallStubForGetter(member, selectors, defineInstanceMember);
       }
     } else if (member.kind == ElementKind.FUNCTION) {
       if (compiler.universe.hasGetter(member, compiler)) {
-        compiler.emitter.emitDynamicFunctionGetter(member,
-                                                   defineInstanceMember);
+        emitDynamicFunctionGetter(member, defineInstanceMember);
       }
     }
   }