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

Source/web/SourceBufferPrivateImpl.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 31 matching lines @@
 class SourceBufferPrivateImpl : public WebCore::SourceBufferPrivate {
 public:
     explicit SourceBufferPrivateImpl(PassOwnPtr<WebSourceBuffer>);
     virtual ~SourceBufferPrivateImpl() { }
 
     // SourceBufferPrivate methods.
     virtual PassRefPtr<WebCore::TimeRanges> buffered();
     virtual void append(const unsigned char* data, unsigned length);
     virtual void abort();
     virtual bool setTimestampOffset(double);
+    virtual void setAppendWindowStart(double);
+    virtual void setAppendWindowEnd(double);
     virtual void removedFromMediaSource();
 
 private:
     OwnPtr<WebSourceBuffer> m_sourceBuffer;
 };
 
 
 }
 
 #endif