Reduce imprecision of incremental marking.

src/heap.h

 // 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 1394 matching lines @@
 
   bool ShouldWeGiveBackAPageToTheOS() {
     last_empty_page_was_given_back_to_the_os_ =
         !last_empty_page_was_given_back_to_the_os_;
     return last_empty_page_was_given_back_to_the_os_;
   }
 
   void QueueMemoryChunkForFree(MemoryChunk* chunk);
   void FreeQueuedChunks();
 
+  // Completely clear the Instanceof cache (to stop it keeping objects alive
+  // around a GC).
+  inline void CompletelyClearInstanceofCache();
+
  private:
   Heap();
 
   // This can be calculated directly from a pointer to the heap; however, it is
   // more expedient to get at the isolate directly from within Heap methods.
   Isolate* isolate_;
 
   intptr_t code_range_size_;
   int reserved_semispace_size_;
   int max_semispace_size_;
@@ skipping 223 matching lines @@
   static void ScavengeStoreBufferCallback(Heap* heap,
                                           MemoryChunk* page,
                                           StoreBufferEvent event);
 
   // Performs a major collection in the whole heap.
   void MarkCompact(GCTracer* tracer);
 
   // Code to be run before and after mark-compact.
   void MarkCompactPrologue();
 
-  // Completely clear the Instanceof cache (to stop it keeping objects alive
-  // around a GC).
-  inline void CompletelyClearInstanceofCache();
-
   // Record statistics before and after garbage collection.
   void ReportStatisticsBeforeGC();
   void ReportStatisticsAfterGC();
 
   // Slow part of scavenge object.
   static void ScavengeObjectSlow(HeapObject** p, HeapObject* object);
 
   // Initializes a function with a shared part and prototype.
   // Returns the function.
   // Note: this code was factored out of AllocateFunction such that
@@ skipping 774 matching lines @@
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 } }  // namespace v8::internal
 
 #undef HEAP
 
 #endif  // V8_HEAP_H_