Add some cheap optimization, and another computation limit in the container tracer.

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

Index: sdk/lib/_internal/compiler/implementation/types/container_tracer.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/types/container_tracer.dart	(revision 25104)
+++ sdk/lib/_internal/compiler/implementation/types/container_tracer.dart	(working copy)
@@ -94,13 +94,17 @@
     measure(() {
       SimpleTypesInferrer inferrer = compiler.typesTask.typesInferrer;
       var internal = inferrer.internal;
+      int maxAnalysis = internal.numberOfElementsToAnalyze;
+      int analysisCount = 0;
       // Walk over all created [ContainerTypeMask].
-      internal.concreteTypes.values.forEach((ContainerTypeMask mask) {
+      for (ContainerTypeMask mask in internal.concreteTypes.values) {
         // The element type has already been set for const containers.
-        if (mask.elementType != null) return;
-        mask.elementType = new TracerForConcreteContainer(
-            mask, this, compiler, inferrer).run();
-      });
+        if (mask.elementType != null) continue;
+        TracerForConcreteContainer tracer = new TracerForConcreteContainer(
+            mask, this, compiler, inferrer);
+        mask.elementType = tracer.run();
+        if ((analysisCount += tracer.analysisCount) > maxAnalysis) break;
+      }
     });
   }
 }
@@ -139,6 +143,7 @@
 
   TypeMask potentialType;
   bool continueAnalyzing = true;
+  int analysisCount = 0;
 
   TracerForConcreteContainer(ContainerTypeMask mask,
                              this.tracer,
@@ -148,7 +153,6 @@
         startElement = mask.allocationElement;
 
   TypeMask run() {
-    int analysisCount = 0;
     workList.add(startElement);
     while (!workList.isEmpty) {
       if (workList.length + analysisCount > MAX_ANALYSIS_COUNT) {