Remove unused ExtraData support on exported mediastream objects.

Source/platform/mediastream/RTCSessionDescriptionRequest.h

 /*
  * Copyright (C) 2012 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
@@ 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 RTCSessionDescriptionRequest_h
 #define RTCSessionDescriptionRequest_h
 
 #include "platform/heap/Handle.h"
-#include "wtf/PassOwnPtr.h"
-#include "wtf/text/WTFString.h"
+#include "wtf/Forward.h"
 
 namespace blink {
 class WebRTCSessionDescription;
 
 class RTCSessionDescriptionRequest : public GarbageCollectedFinalized<RTCSessionDescriptionRequest> {
 public:
-    class ExtraData {
-    public:
-        virtual ~ExtraData() { }
-    };
-
     virtual ~RTCSessionDescriptionRequest() { }
 
     virtual void requestSucceeded(const WebRTCSessionDescription&) = 0;
     virtual void requestFailed(const String& error) = 0;
 
-    ExtraData* extraData() const { return m_extraData.get(); }
-    void setExtraData(PassOwnPtr<ExtraData> extraData) { m_extraData = extraData; }
-
-    // Need to eagerly finalize ExtraData.
-    EAGERLY_FINALIZE();
     DEFINE_INLINE_VIRTUAL_TRACE() { }
 
 protected:
     RTCSessionDescriptionRequest() { }
-
-private:
-    OwnPtr<ExtraData> m_extraData;
 };
 
 } // namespace blink
 
 #endif // RTCSessionDescriptionRequest_h