[part 2] Make classes and structures in modules fast-allocated.

Source/modules/mediasource/HTMLVideoElementMediaSource.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 14 matching lines @@
  * 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 HTMLVideoElementMediaSource_h
 #define HTMLVideoElementMediaSource_h
 
 #include "platform/heap/Handle.h"
-#include "wtf/PassRefPtr.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
 class HTMLVideoElement;
 class VideoPlaybackQuality;
 
 class HTMLVideoElementMediaSource {
+    STATIC_ONLY(HTMLVideoElementMediaSource);
 public:
     static VideoPlaybackQuality* getVideoPlaybackQuality(HTMLVideoElement&);
-
-private:
-    HTMLVideoElementMediaSource();
-    ~HTMLVideoElementMediaSource();
 };
 
 }
 
 #endif