RtcVideoDecoder: fall back to SW decode for unsupported profiles/resolutions

RtcVideoDecoder: fall back to SW decode for unsupported profiles/resolutions

RtcVideoDecoder, like GpuVideoDecoder, can verify whether a profile is
supported by querying GpuVideoAcceleratorFactories for supported profiles
and not create a VDA if it can't support it, saving a roundtrip to the GPU
process.

Separately, if a resolution is not supported by the HW decoder, we should
fall back to software decoder, but this can only be handled on Decode(),
since resolution is known from a keyframe, and may change mid-stream.
However, there used to be no way to request a fallback to SW, as WebRTC
treated any error returned from Decode() as stream error and non-fatal, and
kept attempting to Decode() further, after requesting and providing another
keyframe.

With crrev.com/7252a2ba8035c4128917a9558a3e34fc9dbe7c44 in however, we can
now return WEBRTC_VIDEO_CODEC_FALLBACK_SOFTWARE from Decode(), and webrtc
will continue decoding in software decoder, until the next keyframe, when
it will retry Decode(), in case the resolution changed to a supported one.

BUG=487934
TEST=fallback on apprtc

Committed: https://crrev.com/2e9e9a59bdfb3604b7e55975dd927cff90161669
Cr-Commit-Position: refs/heads/master@{#331305}

[Pawel Osciak, 2015-05-20 09:04:56]

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

[Pawel Osciak, 2015-05-20 09:05:02]

ptal

[wuchengli, 2015-05-25 03:18:25]

lgtm

[Pawel Osciak, 2015-05-25 09:10:05]

ptal

[wuchengli, 2015-05-25 09:27:15]

lgtm

[Pawel Osciak, 2015-05-25 09:52:54]

The CQ bit was checked by posciak@chromium.org

[commit-bot: I haz the power, 2015-05-25 09:53:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1150543002/20001

[commit-bot: I haz the power, 2015-05-25 09:59:35]

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

[commit-bot: I haz the power, 2015-05-25 09:59:36]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[Pawel Osciak, 2015-05-25 10:05:08]

posciak@chromium.org changed reviewers:
+ tommi@chromium.org

[Pawel Osciak, 2015-05-25 10:05:09]

tommi@chromium.org: may I have owner stamp please?

[tommi (sloooow) - chröme, 2015-05-25 21:03:26]

The CQ bit was checked by tommi@chromium.org

[tommi (sloooow) - chröme, 2015-05-25 21:03:27]

lgtm

[commit-bot: I haz the power, 2015-05-25 21:03:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1150543002/20001

[commit-bot: I haz the power, 2015-05-25 22:00:44]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-25 22:01:33]

Patchset 2 (id:??) landed as
https://crrev.com/2e9e9a59bdfb3604b7e55975dd927cff90161669
Cr-Commit-Position: refs/heads/master@{#331305}