Track JS allocations as they arrive with no affection on performance when tracking is switched off

test/cctest/cctest.h

Index: test/cctest/cctest.h
diff --git a/test/cctest/cctest.h b/test/cctest/cctest.h
index 193126a0818e91a1aac21a900c0b0db476c7467d..0efcf066b7bb11dd2065b30329a8496ccf51a16a 100644
--- a/test/cctest/cctest.h
+++ b/test/cctest/cctest.h
@@ -71,6 +71,17 @@ typedef v8::internal::EnumSet<CcTestExtensionIds> CcTestExtensionFlags;
   EXTENSION_LIST(DEFINE_EXTENSION_FLAG)
 #undef DEFINE_EXTENSION_FLAG
 
+void RunAndTrackAllocations(void (*test)());
+
+#ifndef TEST_TRACK_ALLOCATIONS
+#define TEST_TRACK_ALLOCATIONS(Name)            \
+  static void Test##Name();                     \
+  TEST(Name##TrackAllocations) {                \
+    RunAndTrackAllocations(&Test##Name);        \
+  }                                             \
+  TEST(Name)
+#endif
+
 class CcTest {
  public:
   typedef void (TestFunction)();
@@ -300,4 +311,41 @@ static inline void SimulateFullSpace(v8::internal::PagedSpace* space) {
 }
 
 
+// Helper class for new allocations tracking and checking.
+// To use checking of JS allocations tracking in a test,
+// use TEST_TRACK_ALLOCATIONS macro or just create an instance
+// of this class.
+class HeapObjectsTracker {
+ public:
+  HeapObjectsTracker() {
+    heap_profiler_ = i::Isolate::Current()->heap_profiler();
+    CHECK_NE(NULL, heap_profiler_);
+
+    heap_profiler_->StartHeapAllocationsRecording();
+
+    HEAP->CollectAllAvailableGarbage();
+    HEAP->CollectAllAvailableGarbage();
+    HEAP->CollectAllAvailableGarbage();
+    untracked_on_start_ = heap_profiler_->FindUntrackedObjects();
+  }
+
+  virtual ~HeapObjectsTracker() {
+    CHECK_GE(0, CountUntrackedObjects());
+    heap_profiler_->StopHeapAllocationsRecording();
+  }
+
+ private:
+  int CountUntrackedObjects() {
+    HEAP->CollectAllAvailableGarbage();
+    HEAP->CollectAllAvailableGarbage();
+    HEAP->CollectAllAvailableGarbage();
+
+    return heap_profiler_->FindUntrackedObjects() - untracked_on_start_;
+  }
+
+  i::HeapProfiler* heap_profiler_;
+  int untracked_on_start_;
+};
+
+
 #endif  // ifndef CCTEST_H_