Make CompilerTask independent of compiler.

pkg/compiler/lib/src/ssa/builder.dart

 // Copyright (c) 2012, 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 'dart:collection';
 
 import 'package:js_runtime/shared/embedded_names.dart';
 
 import '../closure.dart';
 import '../common.dart';
@@ skipping 73 matching lines @@
 
   SyntheticLocal(this.name, this.executableContext);
 
   toString() => 'SyntheticLocal($name)';
 }
 
 class SsaBuilderTask extends CompilerTask {
   final CodeEmitterTask emitter;
   final JavaScriptBackend backend;
   final SourceInformationStrategy sourceInformationFactory;
+  final Compiler compiler;
 
   String get name => 'SSA builder';
 
   SsaBuilderTask(JavaScriptBackend backend, this.sourceInformationFactory)
       : emitter = backend.emitter,
         backend = backend,
-        super(backend.compiler);
+        compiler = backend.compiler,
+        super(backend.compiler.measurer);
 
   DiagnosticReporter get reporter => compiler.reporter;
 
   HGraph build(CodegenWorkItem work) {
     return measure(() {
       Element element = work.element.implementation;
       return reporter.withCurrentElement(element, () {
         SsaBuilder builder = new SsaBuilder(
             work.element.implementation,
             work.resolvedAst,
@@ skipping 8512 matching lines @@
   const _LoopTypeVisitor();
   int visitNode(ast.Node node) => HLoopBlockInformation.NOT_A_LOOP;
   int visitWhile(ast.While node) => HLoopBlockInformation.WHILE_LOOP;
   int visitFor(ast.For node) => HLoopBlockInformation.FOR_LOOP;
   int visitDoWhile(ast.DoWhile node) => HLoopBlockInformation.DO_WHILE_LOOP;
   int visitAsyncForIn(ast.AsyncForIn node) => HLoopBlockInformation.FOR_IN_LOOP;
   int visitSyncForIn(ast.SyncForIn node) => HLoopBlockInformation.FOR_IN_LOOP;
   int visitSwitchStatement(ast.SwitchStatement node) =>
       HLoopBlockInformation.SWITCH_CONTINUE_LOOP;
 }