Merge 217276 "Add media::VideoEncodeAccelerator with WebRTC inte..."

Merge 217276 "Add media::VideoEncodeAccelerator with WebRTC inte..."

> Add media::VideoEncodeAccelerator with WebRTC integration
> 
> * Adds media::VideoEncodeAccelerator class.
> * Add GpuVideoEncodeAccelerator{,Host} classes and appropriate IPC.
> * Integrates into WebRTC stack with RTCVideoEncoderFactory/RTCVideoEncoder.
> * Rename media::GpuVideoDecodeFactories -> media::GpuVideoAcceleratorFactories
>   and generalize for use by the encode accelerator implementations as well.
> 
> BUG=260210
> BUG=170345
> TEST=local build, run on CrOS snow; local build, unittests on desktop Linux
> 
> Review URL: https://chromiumcodereview.appspot.com/20632002

TBR=sheu@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=217691

[kareng, 2013-08-14 23:20:38]

Committed patchset #1 manually as r217691.