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

tools/clang/blink_gc_plugin/tests/inner_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 INNER_CLASS_H_
 #define INNER_CLASS_H_
 
 #include "heap/stubs.h"
 
-namespace WebCore {
+namespace blink {
 
 class SomeObject {
 private:
     class InnerObject : public GarbageCollected<InnerObject> {
     public:
         void trace(Visitor*);
     private:
         Member<InnerObject> m_obj;
     };
 };
 
 }
 
 #endif