clang/blink_gc_plugin: Replace 'WebCore' with 'blink'

tools/clang/blink_gc_plugin/tests/destructor_in_nonfinalized_class.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef DESTRUCTOR_IN_NONFINALIZED_CLASS_H_
 #define DESTRUCTOR_IN_NONFINALIZED_CLASS_H_
 
 #include "heap/stubs.h"
 
-namespace WebCore {
+namespace blink {
 
 class HeapObject : public GarbageCollected<HeapObject> {
 public:
     ~HeapObject();
     void trace(Visitor*);
 private:
     Member<HeapObject> m_obj;
 };
 
 }
 
 #endif