Move map retaining to finalization of incremental marking.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 5804 matching lines @@
 }
 
 
 void CheckMapRetainingFor(int n) {
   FLAG_retain_maps_for_n_gc = n;
   Isolate* isolate = CcTest::i_isolate();
   Heap* heap = isolate->heap();
   Handle<WeakCell> weak_cell = AddRetainedMap(isolate, heap);
   CHECK(!weak_cell->cleared());
   for (int i = 0; i < n; i++) {
+    heap->StartIncrementalMarking();
+    SimulateIncrementalMarking(heap);
     heap->CollectGarbage(OLD_SPACE);
   }
   CHECK(!weak_cell->cleared());
+  heap->StartIncrementalMarking();
+  SimulateIncrementalMarking(heap);
   heap->CollectGarbage(OLD_SPACE);
   CHECK(weak_cell->cleared());
 }
 
 
 TEST(MapRetaining) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
   CheckMapRetainingFor(FLAG_retain_maps_for_n_gc);
   CheckMapRetainingFor(0);
@@ skipping 609 matching lines @@
   isolate->IncrementJsCallsFromApiCounter();
   isolate->IncrementJsCallsFromApiCounter();
   isolate->IncrementJsCallsFromApiCounter();
   calls_per_ms = memory_reducer->SampleAndGetJsCallsPerMs(4);
   CheckDoubleEquals(2, calls_per_ms);
 }
 
 
 }  // namespace internal
 }  // namespace v8