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

tools/clang/blink_gc_plugin/tests/virtual_and_trace_after_dispatch.cpp

 // 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.
 
 #include "virtual_and_trace_after_dispatch.h"
 
-namespace WebCore {
+namespace blink {
 
 static B* toB(A* a) { return static_cast<B*>(a); }
 
 void A::trace(Visitor* visitor)
 {
     switch (m_type) {
     case TB:
         toB(this)->traceAfterDispatch(visitor);
         break;
     }
 }
 
 void A::traceAfterDispatch(Visitor* visitor)
 {
 }
 
 void B::traceAfterDispatch(Visitor* visitor)
 {
     visitor->trace(m_a);
     A::traceAfterDispatch(visitor);
 }
 
 }