Remove some asserts to speed up debug mode.

src/incremental-marking-inl.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 125 matching lines @@
 }
 
 
 void IncrementalMarking::WhiteToGreyAndPush(HeapObject* obj, MarkBit mark_bit) {
   WhiteToGrey(obj, mark_bit);
   marking_deque_.PushGrey(obj);
 }
 
 
 void IncrementalMarking::WhiteToGrey(HeapObject* obj, MarkBit mark_bit) {
-  ASSERT(Marking::MarkBitFrom(obj) == mark_bit);
-  ASSERT(obj->Size() >= 2*kPointerSize);
-  ASSERT(IsMarking());
   Marking::WhiteToGrey(mark_bit);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_INCREMENTAL_MARKING_INL_H_