Remove MEDIA_SOURCE feature define.

Source/WebKit/chromium/src/WebMediaSourceImpl.h

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebMediaSourceImpl_h
 #define WebMediaSourceImpl_h
 
-#if ENABLE(MEDIA_SOURCE)
-
 #include "MediaSource.h"
 #include "WebMediaSource.h"
 
 namespace WebKit {
 
 class WebMediaSourceImpl : public WebMediaSource {
 public:
     WebMediaSourceImpl(PassRefPtr<WebCore::MediaSource>);
     virtual ~WebMediaSourceImpl();
 
     // WebMediaSource methods.
     virtual void open(WebMediaSourceClient*);
 
 private:
     RefPtr<WebCore::MediaSource> m_mediaSource;
 };
 
 }
 
 #endif
-
-#endif