WebVR: Add sanity checks for decoded pose index values

WebVR: Add sanity checks for decoded pose index values

We seem to be getting glitches in the display pipeline that
manifest as all-white pixels for a few frames before regular
rendering starts. These get misinterpreted as an invalid
pose index, and apparently supplying a wrong pose to GVR
permanently breaks reprojection for that instance.

Add sanity checks to help identify and avoid bad pose values
during initialization.

BUG=667327
Review-Url: https://codereview.chromium.org/2541023003
Cr-Commit-Position: refs/heads/master@{#435866}
(cherry picked from commit 490f4294847d427265ae138de9932926d61b885e)

Committed: https://chromium.googlesource.com/chromium/src/+/ff9b716dacc4003878af2122770986ce03f574f6

[bajones, 2016-12-02 21:52:20]

Description was changed from

==========
WebVR: Add sanity checks for decoded pose index values

We seem to be getting glitches in the display pipeline that
manifest as all-white pixels for a few frames before regular
rendering starts. These get misinterpreted as an invalid
pose index, and apparently supplying a wrong pose to GVR
permanently breaks reprojection for that instance.

Add sanity checks to help identify and avoid bad pose values
during initialization.

BUG=667327

Review-Url: https://codereview.chromium.org/2541023003
Cr-Commit-Position: refs/heads/master@{#435866}
(cherry picked from commit 490f4294847d427265ae138de9932926d61b885e)
==========

to

==========
WebVR: Add sanity checks for decoded pose index values

We seem to be getting glitches in the display pipeline that
manifest as all-white pixels for a few frames before regular
rendering starts. These get misinterpreted as an invalid
pose index, and apparently supplying a wrong pose to GVR
permanently breaks reprojection for that instance.

Add sanity checks to help identify and avoid bad pose values
during initialization.

BUG=667327

Review-Url: https://codereview.chromium.org/2541023003
Cr-Commit-Position: refs/heads/master@{#435866}
(cherry picked from commit 490f4294847d427265ae138de9932926d61b885e)

Committed:
https://chromium.googlesource.com/chromium/src/+/ff9b716dacc4003878af21227709...
==========

[bajones, 2016-12-02 21:52:21]

Committed patchset #1 (id:1) manually as
ff9b716dacc4003878af2122770986ce03f574f6.