Do not create GpuVideoAcceleratorFactories if kDisableGpuCompositing is set

Do not create GpuVideoAcceleratorFactories if kDisableGpuCompositing is set

Fixes [ERROR:video_layer_impl.cc] Not implemented reached in virtual void
cc::VideoLayerImpl::AppendQuads(cc::RenderPass *, cc::AppendQuadsData *)

BUG=606282
R=kbr@chromium.org, piman@chromium.org, zmo@chromium.org

[Julien Isorce Samsung, 2016-05-11 13:49:53]

With Mesa software gl driver I could reproduce the error mentioned in the bug,
i.e. [ERROR:video_layer_impl.cc] Not implemented reached in virtual void
cc::VideoLayerImpl::AppendQuads(cc::RenderPass *, cc::AppendQuadsData *) that
appears for every frame when playing a video.

I think I could reproduce this problem because now gpu process is active for
webgl readback but gpu compositing is off which confuses the media video
machinery.

This CL fixes the problem but since solution 2 is also working I am wondering if
the solution 1 is too radical. It looks to me that GpuVideoAcceleratorFactories
is only useful when gpu compositing is on. But perhaps I am missing a
configuration where it is useful.

Please have a look. Thx!

[Julien Isorce Samsung, 2016-05-11 13:50:05]

The CQ bit was checked by j.isorce@samsung.com to run a CQ dry run

[commit-bot: I haz the power, 2016-05-11 13:50:19]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1968933003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1968933003/1

[commit-bot: I haz the power, 2016-05-11 14:54:46]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-05-11 14:54:46]

Dry run: This issue passed the CQ dry run.

[piman, 2016-05-12 00:54:25]

Daniele essentially implemented solution 2 in
https://codereview.chromium.org/1972783002/ - He and I think that's the right
approach.

[Julien Isorce Samsung, 2016-05-16 09:25:07]

Description was changed from

==========
Do not create GpuVideoAcceleratorFactories if kDisableGpuCompositing is set

Fixes [ERROR:video_layer_impl.cc] Not implemented reached in virtual void
cc::VideoLayerImpl::AppendQuads(cc::RenderPass *, cc::AppendQuadsData *)

BUG=606282

R=kbr@chromium.org, piman@chromium.org, zmo@chromium.org
==========

to

==========
Do not create GpuVideoAcceleratorFactories if kDisableGpuCompositing is set

Fixes [ERROR:video_layer_impl.cc] Not implemented reached in virtual void
cc::VideoLayerImpl::AppendQuads(cc::RenderPass *, cc::AppendQuadsData *)

BUG=606282

R=kbr@chromium.org, piman@chromium.org, zmo@chromium.org
==========

[Julien Isorce Samsung, 2016-05-16 09:30:40]

On 2016/05/12 00:54:25, piman OOO back 2016-5-16 wrote:
> Daniele essentially implemented solution 2 in
> https://codereview.chromium.org/1972783002/ - He and I think that's the right
> approach.

No problem, as I can see from emails it was quite urgent issue so I guess that's
why Daniele decided to create a new CL instead of reviewing mine. So I am going
to close it now.