Add NOTREACHED to HeapObjectHeader::markDead()

third_party/WebKit/Source/platform/heap/HeapPage.h

 /*
  * Copyright (C) 2013 Google Inc. 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
@@ skipping 907 matching lines @@
   ASSERT(isMarked());
   m_encoded &= ~headerMarkBitMask;
 }
 
 NO_SANITIZE_ADDRESS inline bool HeapObjectHeader::isDead() const {
   ASSERT(checkHeader());
   return m_encoded & headerDeadBitMask;
 }
 
 NO_SANITIZE_ADDRESS inline void HeapObjectHeader::markDead() {
+  // A Dead state should not happen in a per-thread heap world.
+  // TODO(haraken): Remove code to handle the Dead state.
+  CHECK(false);
   ASSERT(checkHeader());
   ASSERT(!isMarked());
   m_encoded |= headerDeadBitMask;
 }
 
 inline Address NormalPageArena::allocateObject(size_t allocationSize,
                                                size_t gcInfoIndex) {
   if (LIKELY(allocationSize <= m_remainingAllocationSize)) {
     Address headerAddress = m_currentAllocationPoint;
     m_currentAllocationPoint += allocationSize;
@@ skipping 10 matching lines @@
   return outOfLineAllocate(allocationSize, gcInfoIndex);
 }
 
 inline NormalPageArena* NormalPage::arenaForNormalPage() const {
   return static_cast<NormalPageArena*>(arena());
 }
 
 }  // namespace blink
 
 #endif  // HeapPage_h