Rename WebCore namespace to blink in Platform

Source/platform/PermissionCallbacks.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 PermissionCallbacks_h
 #define PermissionCallbacks_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/Functional.h"
 #include "wtf/Noncopyable.h"
 #include "wtf/PassOwnPtr.h"
 
-namespace WebCore {
+namespace blink {
 
 class PLATFORM_EXPORT PermissionCallbacks {
     WTF_MAKE_NONCOPYABLE(PermissionCallbacks);
 public:
     static PassOwnPtr<PermissionCallbacks> create(const Closure& allowed, const Closure& denied);
     virtual ~PermissionCallbacks() { }
 
     void onAllowed() { m_allowed(); }
     void onDenied() { m_denied(); }
 
 private:
     PermissionCallbacks(const Closure& allowed, const Closure& denied);
 
     Closure m_allowed;
     Closure m_denied;
 };
 
-} // namespace WebCore
+} // namespace blink
 
 #endif // PermissionCallbacks_h