Use new ASAN APIs for scanning ASAN fake stacks during garbage collection.

Source/platform/heap/ThreadState.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 460 matching lines @@
     PersistentNode* roots() const { return m_persistents.get(); }
 
     // List of global persistent roots not owned by any particular thread.
     // globalRootsMutex must be acquired before any modifications.
     static PersistentNode* globalRoots();
     static Mutex& globalRootsMutex();
 
     // Visit local thread stack and trace all pointers conservatively.
     void visitStack(Visitor*);
 
+    // Visit the asan fake stack frame corresponding to a slot on the
+    // real machine stack if there is one.
+    void visitAsanFakeStackForPointer(Visitor*, Address);
+
     // Visit all persistents allocated on this thread.
     void visitPersistents(Visitor*);
 
     // Checks a given address and if a pointer into the oilpan heap marks
     // the object to which it points.
     bool checkAndMarkPointer(Visitor*, Address);
 
     void pushWeakObjectPointerCallback(void*, WeakPointerCallback);
     bool popAndInvokeWeakPointerCallback(Visitor*);
 
@@ skipping 67 matching lines @@
     bool m_inGC;
     BaseHeap* m_heaps[NumberOfHeaps];
     OwnPtr<HeapContainsCache> m_heapContainsCache;
     HeapStats m_stats;
     HeapStats m_statsAfterLastGC;
 
     Vector<OwnPtr<CleanupTask> > m_cleanupTasks;
     bool m_isCleaningUp;
 
     CallbackStack* m_weakCallbackStack;
+
+#if defined(ADDRESS_SANITIZER) && !OS(WIN)
+    void* m_asanFakeStack;
+#endif
 };
 
 template<ThreadAffinity affinity> class ThreadStateFor;
 
 template<> class ThreadStateFor<MainThreadOnly> {
 public:
     static ThreadState* state()
     {
         // This specialization must only be used from the main thread.
         ASSERT(ThreadState::isMainThread());
         return ThreadState::mainThreadState();
     }
 };
 
 template<> class ThreadStateFor<AnyThread> {
 public:
     static ThreadState* state() { return ThreadState::current(); }
 };
 
 }
 
 #endif // ThreadState_h