Replace v8::Handle with v8::Local in core/testing/*

Source/core/testing/GCObservation.cpp

 /*
  * 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 27 matching lines @@
     data.GetParameter()->setWasCollected();
 }
 
 void GCObservation::setWasCollected()
 {
     ASSERT(!wasCollected());
     m_observed.clear();
     m_collected = true;
 }
 
-GCObservation::GCObservation(v8::Handle<v8::Value> observedValue)
+GCObservation::GCObservation(v8::Local<v8::Value> observedValue)
     : m_observed(v8::Isolate::GetCurrent(), observedValue)
     , m_collected(false)
 {
     m_observed.setWeak(this, setWeakCallbackForGCObservation);
 }
 
 } // namespace blink