Add kEnableWebRtcHWVp8Encoding to GPU process.

Add kEnableWebRtcHWVp8Encoding to GPU process.

VideoEncodeAccelerator::GetSupportedProfiles now runs in GPU
process because the profiles were added to GPUInfo. Add
kEnableWebRtcHWVp8Encoding to GPU process to fix the missing
encode profile.

BUG=418762
TEST=Run apprtc loopback and check the histogram.

Committed: https://crrev.com/ebd596bdd2b8ec66884d7f3a41a7f171cd11bf2c
Cr-Commit-Position: refs/heads/master@{#297445}

[wuchengli, 2014-09-30 09:06:40]

wuchengli@chromium.org changed reviewers:
+ piman@chromium.org, posciak@chromium.org

[Pawel Osciak, 2014-09-30 09:07:19]

lgtm

[wuchengli, 2014-09-30 09:07:25]

PTAL

[piman, 2014-09-30 14:06:00]

lgtm

[wuchengli, 2014-09-30 14:27:24]

The CQ bit was checked by wuchengli@chromium.org

[commit-bot: I haz the power, 2014-09-30 14:27:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/618633002/1

[commit-bot: I haz the power, 2014-09-30 15:26:15]

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

[commit-bot: I haz the power, 2014-09-30 15:26:16]

Try jobs failed on following builders:
  linux_chromium_gn_dbg on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[Pawel Osciak, 2014-09-30 17:26:12]

The CQ bit was checked by posciak@chromium.org

[commit-bot: I haz the power, 2014-09-30 17:26:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/618633002/1

[commit-bot: I haz the power, 2014-09-30 17:40:04]

Committed patchset #1 (id:1) as c3d806c14cefde6a1715949bb9dec2897747c343

[commit-bot: I haz the power, 2014-09-30 17:40:40]

Patchset 1 (id:??) landed as
https://crrev.com/ebd596bdd2b8ec66884d7f3a41a7f171cd11bf2c
Cr-Commit-Position: refs/heads/master@{#297445}