Add Blink side support for SourceBuffer.appendWindowStart & SourceBuffer.appendWindowEnd.

Source/modules/mediasource/SourceBuffer.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 44 matching lines @@
 
     // SourceBuffer.idl methods
     bool updating() const { return m_updating; }
     PassRefPtr<TimeRanges> buffered(ExceptionState&) const;
     double timestampOffset() const;
     void setTimestampOffset(double, ExceptionState&);
     void appendBuffer(PassRefPtr<ArrayBuffer> data, ExceptionState&);
     void appendBuffer(PassRefPtr<ArrayBufferView> data, ExceptionState&);
     void abort(ExceptionState&);
     void remove(double start, double end, ExceptionState&);
+    double appendWindowStart() const;
+    void setAppendWindowStart(double, ExceptionState&);
+    double appendWindowEnd() const;
+    void setAppendWindowEnd(double, ExceptionState&);
 
     void abortIfUpdating();
     void removedFromMediaSource();
 
     // ActiveDOMObject interface
     virtual bool hasPendingActivity() const OVERRIDE;
     virtual void stop() OVERRIDE;
 
     // EventTarget interface
     virtual ScriptExecutionContext* scriptExecutionContext() const OVERRIDE;
@@ skipping 20 matching lines @@
 
     void removeTimerFired(Timer<SourceBuffer>*);
 
     OwnPtr<SourceBufferPrivate> m_private;
     MediaSource* m_source;
     GenericEventQueue* m_asyncEventQueue;
     EventTargetData m_eventTargetData;
 
     bool m_updating;
     double m_timestampOffset;
+    double m_appendWindowStart;
+    double m_appendWindowEnd;
 
     Vector<unsigned char> m_pendingAppendData;
     Timer<SourceBuffer> m_appendBufferTimer;
 
     double m_pendingRemoveStart;
     double m_pendingRemoveEnd;
     Timer<SourceBuffer> m_removeTimer;
 };
 
 } // namespace WebCore
 
 #endif