Revert r27992: some browser tests fail.

sdk/lib/_internal/compiler/implementation/compiler.dart

Index: sdk/lib/_internal/compiler/implementation/compiler.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/compiler.dart	(revision 27994)
+++ sdk/lib/_internal/compiler/implementation/compiler.dart	(working copy)
@@ -533,6 +533,7 @@
   EnqueueTask enqueuer;
   DeferredLoadTask deferredLoadTask;
   MirrorUsageAnalyzerTask mirrorUsageAnalyzerTask;
+  ContainerTracer containerTracer;
   String buildId;
 
   static const SourceString MAIN = const SourceString('main');
@@ -638,6 +639,7 @@
       closureToClassMapper = new closureMapping.ClosureTask(this, closureNamer),
       checker = new TypeCheckerTask(this),
       typesTask = new ti.TypesTask(this),
+      containerTracer = new ContainerTracer(this),
       constantHandler = new ConstantHandler(this, backend.constantSystem),
       deferredLoadTask = new DeferredLoadTask(this),
       mirrorUsageAnalyzerTask = new MirrorUsageAnalyzerTask(this),