Revert of Prime the landing pad for the new video rendering pipeline.

Revert of Prime the landing pad for the new video rendering pipeline. (patchset #9 id:200001 of https://codereview.chromium.org/1053113002/)

Reason for revert:
Actually, given the complexity of this change (not a one-line Cast fix) and the fact that we have broken Cast trybots running @ 100% right now (http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linux/), I'm going to revert this. I'm working on a brief patch of what I expect would need to be done for Cast and will upload/mail shortly.

Original issue's description:
> Prime the landing pad for the new video rendering pipeline.
>
> This is not a functional change, it only updates the interfaces and
> call sites in preparation for switching to a vsync based video
> rendering pipeline.
>
> Some notes:
> - Plumbs a VideoRendererSink into the the rendering pipeline; similar to
> how we have an AudioRendererSink.
> - A couple VideoRendererSink mocks are introduced which will be short
> lived. Like audio, we will need fakes which can pump consumption tasks.
> - The "PaintCB" callback has been temporarily placed on the new sink
> interface such that in the field experiments can be run comparing the
> performance of the video rendering approaches.
> - Finally nukes Player_X11 since setting up a vsync renderer just for
> unused tool code isn't worth the effort.
> - Since compositor callbacks may stop due to visibility changes, the
> new VideoRendererImpl will use a countdown timer to pump video playback
> as frames expire; expired frames will not count as dropped.
> - Since canvas/WebGL requires frame updates in the background a new
> method has been added to VideoFrameCompositor to return the current
> frame if it was updated with 250ms, or to request a new one and return
> the updated one.
>
> Subsequent work:
> - sunnyps@ will be switching VideoFrameProviderClientImpl over to using
> a BeginFrameObserver, which will ultimately drive the Render() callbacks.
> - dalecurtis@ will land the VideoRendererAlgorithm which powers the new
> rendering pipeline.
>
> BUG=439548
> TEST=everything works as is.
>
> Committed: https://crrev.com/e7f41df2541aea7c99f7965874f9c5ce901899e5
> Cr-Commit-Position: refs/heads/master@{#325183}

TBR=xhwang@chromium.org,sunnyps@chromium.org,brianderson@chromium.org,enne@chromium.org,dpranke@chromium.org,danakj@chromium.org,dalecurtis@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=439548
Committed: https://crrev.com/24413fda915450e43423cfe3902f887b6a937ae8
Cr-Commit-Position: refs/heads/master@{#325187}

[gunsch, 2015-04-15 06:01:36]

Created Revert of Prime the landing pad for the new video rendering pipeline.

[commit-bot: I haz the power, 2015-04-15 06:02:31]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1052493005/1

[commit-bot: I haz the power, 2015-04-15 06:03:57]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-15 06:04:49]

Patchset 1 (id:??) landed as
https://crrev.com/24413fda915450e43423cfe3902f887b6a937ae8
Cr-Commit-Position: refs/heads/master@{#325187}