Do not zero-initialize RawPtr.

Source/wtf/RawPtr.h

 /*
  * Copyright (C) 2014 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 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WTF_RawPtr_h
 #define WTF_RawPtr_h
 
 #include <algorithm>
+#include <stdint.h>
+
 #include "wtf/HashTableDeletedValueType.h"
 
 // RawPtr is a simple wrapper for a raw pointer that provides the
 // interface (get, clear) of other pointer types such as RefPtr,
 // Persistent and Member. This is used for the Blink garbage
 // collection work in order to be able to write shared code that will
 // use reference counting or garbage collection based on a
 // compile-time flag.
 
 namespace WTF {
 
 template<typename T>
 class RawPtr {
     WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(RawPtr);
     WTF_DISALLOW_ZERO_ASSIGNMENT(RawPtr);
 public:
-    RawPtr() : m_ptr(0) { }
+    RawPtr()
+    {
+#ifndef NDEBUG
+        m_ptr = reinterpret_cast<T*>(rawPtrZapValue);
+#endif
+    }
     RawPtr(std::nullptr_t) : m_ptr(0) { }
     RawPtr(T* ptr) : m_ptr(ptr) { }
     explicit RawPtr(T& reference) : m_ptr(&reference) { }
     RawPtr(const RawPtr& other)
         : m_ptr(other.get())
     {
     }
 
     template<typename U>
     RawPtr(const RawPtr<U>& other)
@@ skipping 47 matching lines @@
     bool operator!() const { return !m_ptr; }
 
     void swap(RawPtr& o)
     {
         std::swap(m_ptr, o.m_ptr);
     }
 
     static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); }
 
 private:
+    static const uintptr_t rawPtrZapValue = 0x3a3a3a3a;
     T* m_ptr;
 };
 
 template<typename T, typename U> inline RawPtr<T> static_pointer_cast(const RawPtr<U>& p)
 {
     return RawPtr<T>(static_cast<T*>(p.get()));
 }
 
 template<typename T> inline T* getPtr(const RawPtr<T>& p)
 {
     return p.get();
 }
 
 } // namespace WTF
 
 using WTF::RawPtr;
 
 #endif