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

tools/clang/blink_gc_plugin/tests/stack_allocated.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 STACK_ALLOCATED_H_
 #define STACK_ALLOCATED_H_
 
 #include "heap/stubs.h"
 
-namespace WebCore {
+namespace blink {
 
 class HeapObject;
 
 class PartObject {
     DISALLOW_ALLOCATION();
 private:
     Member<HeapObject> m_obj; // Needs tracing.
 };
 
 class StackObject {
@@ skipping 17 matching lines @@
 
 // STACK_ALLOCATED is inherited.
 class DerivedStackObject : public StackObject {
 private:
     AnotherStackObject m_anotherPart; // Also fine.
 };
 
 }
 
 #endif