Cleanup namespace usage from animation to exported in platform/

Source/platform/exported/WebAudioBus.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 21 matching lines @@
 
 namespace blink {
 class AudioBus : public ThreadSafeRefCounted<AudioBus> {
 };
 } // namespace blink
 #endif
 
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
 
-using namespace blink;
-
 namespace blink {
 
 class WebAudioBusPrivate : public AudioBus {
 };
 
 void WebAudioBus::initialize(unsigned numberOfChannels, size_t length, double sampleRate)
 {
 #if ENABLE(WEB_AUDIO)
     RefPtr<AudioBus> audioBus = AudioBus::create(numberOfChannels, length);
     audioBus->setSampleRate(sampleRate);
@@ skipping 88 matching lines @@
     RefPtr<AudioBus> audioBus(adoptRef(static_cast<AudioBus*>(m_private)));
     m_private = 0;
     return audioBus;
 #else
     ASSERT_NOT_REACHED();
     return nullptr;
 #endif
 }
 
 } // namespace blink