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

tools/clang/blink_gc_plugin/tests/cycle_super_neg.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 CYCLE_SUPER_NEG_H_
 #define CYCLE_SUPER_NEG_H_
 
 #include "heap/stubs.h"
 
-namespace WebCore {
+namespace blink {
 
 class C;
 
 // The chain:
 //   C -per-> B -sup-> A -sub-> D -ref-> C
 // is not a leaking cycle, because the super-class relationship
 // should not transitively imply sub-class relationships.
 // I.e. B -/-> D
 
 class A : public GarbageCollectedFinalized<A> {
@@ skipping 14 matching lines @@
 class D : public A {
 public:
     virtual void trace(Visitor*);
 private:
     RefPtr<C> m_c;
 };
 
 }
 
 #endif