Reland: Use GpuMemoryBufferVideoFramePool for WebMediaPlayerMS and MediaStreamVideoRendererSink

Reland: Use GpuMemoryBufferVideoFramePool for WebMediaPlayerMS and MediaStreamVideoRendererSink

Relanding after expanding a DCHECK on CopyFrameToYV12() of wedmediaplayer_ms.cc

TBR=dcastagna@chromium.org, phoglund@chromium.org, mcasas@chromium.org, sievers@chromium.org, xhwang@chromium.org, rationale: this patch is equivalent
to the already LGTMd

Original description ---------------------------------------------------
Use GpuMemoryBufferVideoFramePool for WebMediaPlayerMS and MediaStreamVideoRendererSink

MediaStreamVideoRendererSink is the common sink for video playback where we receive both the local camera capture frame and all the remote capture frames from peer connections. They are all hooked to the MediaStream elements.

This CL follows dcastagna's CL that applies asynchronous copies to WebMediaPlayerimpl [0].
[0] https://codereview.chromium.org/1273943002/

BUG=440843, 503835
TEST=
On Linux:
- With and Without the kUseGpuMemoryBuffersForCapture flag, AppRTC loopback runs as expected.
- With and Without the kEnableGpuMemoryBufferVideoFrames flag, AppRTC loopback runs as expected

Committed: https://crrev.com/d49c3945570e7eff2ce728927f8c9fecd04f3487
Cr-Commit-Position: refs/heads/master@{#353839}

patch from issue 1358883003 at patchset 310001 (http://crrev.com/1358883003#ps310001)

Committed: https://crrev.com/c1463d52f046f20244ac7c2d571c7578ff686105
Cr-Commit-Position: refs/heads/master@{#354087}

[emircan, 2015-10-14 18:27:13]

The CQ bit was checked by emircan@chromium.org

[commit-bot: I haz the power, 2015-10-14 18:28:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1407703003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1407703003/1

[commit-bot: I haz the power, 2015-10-14 19:47:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-14 19:48:43]

Patchset 1 (id:??) landed as
https://crrev.com/c1463d52f046f20244ac7c2d571c7578ff686105
Cr-Commit-Position: refs/heads/master@{#354087}