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

tools/clang/blink_gc_plugin/tests/cycle_ptrs.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_PTRS_H_
 #define CYCLE_PTRS_H_
 
 #include "heap/stubs.h"
 
-namespace WebCore {
+namespace blink {
 
 class B;
 class C;
 class D;
 class E;
 
 // This contains a leaking cycle:
 // E -per-> A -mem-> B -ref-> C -own-> D -own-vec-> E
 
 // The traced cycle from A -> B -> A does not leak.
@@ skipping 24 matching lines @@
 };
 
 class E {
 private:
     Persistent<A> m_a;
 };
 
 }
 
 #endif