Fixes video to canvas drawing. The draw operationwas not updating the video

past the first frame.  Added a call to notifyPixelsChanged on the bitmap to 
invalidate the associated texture chache entry, so that the frame will update
correctly.

BUG=57695
TEST=http://www.craftymind.com/factory/html5video/CanvasVideo.html

Review URL: http://codereview.chromium.org/7572027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@95535 0039d316-1c4b-4281-b951-d872f2087c98

webkit/glue/media/video_renderer_impl.cc

@@ -176,6 +176,7 @@ void VideoRendererImpl::SlowPaint(media::VideoFrame* video_frame,
                              video_frame->stride(media::VideoFrame::kUPlane),
                              bitmap_.rowBytes(),
                              yuv_type);
+    bitmap_.notifyPixelsChanged();
     bitmap_.unlockPixels();
   }