Revert "Add concept of whether video renderer supports rotation."

This reverts commit 0ad48935fc.

TBR=guoweis@webrtc.org

BUG=

Review URL: https://webrtc-codereview.appspot.com/41199004

Cr-Commit-Position: refs/heads/master@{#8663}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8663 4adac7df-926f-26a2-2b94-8c16560cd09d

talk/media/base/videorenderer.h

@@ -42,10 +42,7 @@ class VideoFrame;
 class VideoRenderer {
  public:
   virtual ~VideoRenderer() {}
-  // Called when the video has changed size. This is also used as an
-  // initialization method to set the UI size before any video frame
-  // rendered. webrtc::ExternalRenderer's FrameSizeChange will invoke this when
-  // it's called or later when a VideoRenderer is attached.
+  // Called when the video has changed size.
   virtual bool SetSize(int width, int height, int reserved) = 0;
   // Called when a new frame is available for display.
   virtual bool RenderFrame(const VideoFrame *frame) = 0;