Don't report VAAPI failures to UMA for platforms that don't support it

Don't report VAAPI failures for UMA for platforms that don't support it.

On startup, VaapiWrapper::GetSupportedEncodeProfiles is
called to query HW encoder capabilities to fill GpuInfo
with. On VM test however there is no libva present, so we
error out, but also attempt to report an error to UMA,
which blocks and the GPU process gets killed by the GPU
watchdog.

We don't need to report failures on GetSupportedEncodeProfiles
however, as we will report them later when we attempt
to encode anyway.

BUG=402182
TEST=test lumpy under kvm and check chrome is not blocked by
GetSupportedEncodeProfiles

Committed: https://crrev.com/4505d0f3dc0bd9b96db7275f0ae33b7f841ebaf1
Cr-Commit-Position: refs/heads/master@{#297564}

[henryhsu, 2014-09-30 13:43:48]

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

[henryhsu, 2014-09-30 13:43:49]

PTAL.
How to use buildbot to verify entire flow?

[wuchengli, 2014-09-30 14:34:36]

What's the complete stack trace when it hanged? Why does it hangs in VM but not
on real devices?

Maybe one of the trybots run VMTests? Run "git cl try" to test the CL on all
bots.

[wuchengli, 2014-09-30 14:38:02]

s/blocking function in GetSupportedEncodeProfiles/GetSupportedEncodeProfiles
hangs/

[Pawel Osciak, 2014-10-01 00:09:31]

The CQ bit was checked by posciak@chromium.org

[Pawel Osciak, 2014-10-01 00:09:32]

lgtm

[commit-bot: I haz the power, 2014-10-01 00:10:51]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/613223002/1

[commit-bot: I haz the power, 2014-10-01 01:01:15]

Committed patchset #1 (id:1) as 0c0b3394d0b3a7225353353b05515178f485d9aa

[commit-bot: I haz the power, 2014-10-01 01:02:08]

Patchset 1 (id:??) landed as
https://crrev.com/4505d0f3dc0bd9b96db7275f0ae33b7f841ebaf1
Cr-Commit-Position: refs/heads/master@{#297564}