Reduce imprecision of incremental marking.

src/heap.cc

 // Copyright 2011 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 632 matching lines @@
       JSFunctionResultCache::cast(caches->get(i))->Clear();
     }
     // Get the next context:
     context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
   }
 }
 
 
 
 void Heap::ClearNormalizedMapCaches() {
-  if (isolate_->bootstrapper()->IsActive()) return;
+  if (isolate_->bootstrapper()->IsActive() &&
+      !incremental_marking()->IsMarking()) {
+    return;
+  }
 
   Object* context = global_contexts_list_;
   while (!context->IsUndefined()) {
     Context::cast(context)->normalized_map_cache()->Clear();
     context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
   }
 }
 
 
 void Heap::UpdateSurvivalRateTrend(int start_new_space_size) {
@@ skipping 5452 matching lines @@
   }
   isolate_->heap()->store_buffer()->Filter(MemoryChunk::ABOUT_TO_BE_FREED);
   for (chunk = chunks_queued_for_free_; chunk != NULL; chunk = next) {
     next = chunk->next_chunk();
     isolate_->memory_allocator()->Free(chunk);
   }
   chunks_queued_for_free_ = NULL;
 }
 
 } }  // namespace v8::internal