Remove most direct uses of 'backend' and 'compiler' in GraphBuilder.

pkg/compiler/lib/src/native/ssa.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.
 
 import '../common.dart';
 import '../constants/values.dart';
 import '../elements/resolution_types.dart';
 import '../elements/elements.dart';
 import '../js/js.dart' as js;
-import '../js_backend/js_backend.dart';
 import '../js_emitter/js_emitter.dart' show NativeEmitter;
 import '../ssa/builder.dart' show SsaBuilder;
 import '../ssa/nodes.dart' show HInstruction, HForeignCode, HReturn;
 import '../tree/tree.dart';
 import '../universe/side_effects.dart' show SideEffects;
 
 final RegExp nativeRedirectionRegExp = new RegExp(r'^[a-zA-Z][a-zA-Z_$0-9]*$');
 
 void handleSsaNative(SsaBuilder builder, Expression nativeBody) {
   MethodElement element = builder.target;
   NativeEmitter nativeEmitter = builder.nativeEmitter;
-  JavaScriptBackend backend = builder.backend;
 
   HInstruction convertDartClosure(
       ParameterElement parameter, ResolutionFunctionType type) {
     HInstruction local = builder.localsHandler.readLocal(parameter);
     ConstantValue arityConstant =
         builder.constantSystem.createInt(type.parameterTypes.length);
     HInstruction arity =
         builder.graph.addConstant(arityConstant, builder.closedWorld);
     // TODO(ngeoffray): For static methods, we could pass a method with a
     // defined arity.
-    MethodElement helper = backend.helpers.closureConverter;
+    MethodElement helper = builder.helpers.closureConverter;
     builder.pushInvokeStatic(nativeBody, helper, [local, arity]);
     HInstruction closure = builder.pop();
     return closure;
   }
 
   // Check which pattern this native method follows:
   // 1) foo() native;
   //      hasBody = false
   // 2) foo() native "bar";
   //      No longer supported, this is now done with @JSName('foo') and case 1.
   // 3) foo() native "return 42";
   //      hasBody = true
   bool hasBody = false;
-  assert(backend.nativeData.isNativeMember(element));
-  String nativeMethodName = backend.nativeData.getFixedBackendName(element);
+  assert(builder.nativeData.isNativeMember(element));
+  String nativeMethodName = builder.nativeData.getFixedBackendName(element);
   if (nativeBody != null) {
     LiteralString jsCode = nativeBody.asLiteralString();
     String str = jsCode.dartString.slowToString();
     if (nativeRedirectionRegExp.hasMatch(str)) {
       throw new SpannableAssertionFailure(
           nativeBody, "Deprecated syntax, use @JSName('name') instead.");
     }
     hasBody = true;
   }
 
@@ skipping 57 matching lines @@
     LiteralString jsCode = nativeBody.asLiteralString();
     builder.push(new HForeignCode.statement(
         js.js.statementTemplateYielding(
             new js.LiteralStatement(jsCode.dartString.slowToString())),
         <HInstruction>[],
         new SideEffects(),
         null,
         builder.commonMasks.dynamicType));
   }
 }