Handle OffscreenCanvas.convertToBlob exceptions: EncodingError & InvalidStateError

Handle OffscreenCanvas.convertToBlob exceptions: EncodingError & InvalidStateError

This CL handle two new exceptions:
1. EncodingError exception when convertToBlob fails encoding; the test case we
use here is to attempt encoding webp that exceeds max dimension. This is
consistent with new spec change: https://github.com/whatwg/html/pull/2343
2. InvalidStateError exception when convertToBlob is calling on an OffscreenCanvas
without rendering contexts. Spec change needs to be done later on.

Meanwhile, this CL also fixed crash bug in the corner case when convertToBlob
with webp image type fails.

BUG=659260, 563830
Review-Url: https://codereview.chromium.org/2695343002
Cr-Commit-Position: refs/heads/master@{#452935}
Committed: https://chromium.googlesource.com/chromium/src/+/5ce8692f118a0f554fa98574be0c5446b8f0b8fe

[xlai (Olivia), 2017-02-15 21:42:15]

The CQ bit was checked by xlai@chromium.org to run a CQ dry run

[xlai (Olivia), 2017-02-15 21:42:27]

xlai@chromium.org changed reviewers:
+ junov@chromium.org

[commit-bot: I haz the power, 2017-02-15 21:43:14]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-02-16 01:14:24]

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

[commit-bot: I haz the power, 2017-02-16 01:14:25]

Dry run: This issue passed the CQ dry run.

[xlai (Olivia), 2017-02-24 17:17:22]

gentle ping to junov@

[Justin Novosad, 2017-02-24 18:31:07]

lgtm

[xlai (Olivia), 2017-02-24 19:47:55]

The CQ bit was checked by xlai@chromium.org

[commit-bot: I haz the power, 2017-02-24 19:48:43]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-02-24 21:39:58]

CQ is committing da patch.

Bot data: {"patchset_id": 1, "attempt_start_ts": 1487965675037630, "parent_rev":
"e932ed672d61ea3e2e4675aa17715bb2899af788", "commit_rev":
"5ce8692f118a0f554fa98574be0c5446b8f0b8fe"}

[commit-bot: I haz the power, 2017-02-24 21:40:38]

Description was changed from

==========
Handle OffscreenCanvas.convertToBlob exceptions: EncodingError &
InvalidStateError

This CL handle two new exceptions:
1. EncodingError exception when convertToBlob fails encoding; the test case we
use here is to attempt encoding webp that exceeds max dimension. This is
consistent with new spec change: https://github.com/whatwg/html/pull/2343
2. InvalidStateError exception when convertToBlob is calling on an
OffscreenCanvas
without rendering contexts. Spec change needs to be done later on.

Meanwhile, this CL also fixed crash bug in the corner case when convertToBlob
with webp image type fails.

BUG=659260, 563830
==========

to

==========
Handle OffscreenCanvas.convertToBlob exceptions: EncodingError &
InvalidStateError

This CL handle two new exceptions:
1. EncodingError exception when convertToBlob fails encoding; the test case we
use here is to attempt encoding webp that exceeds max dimension. This is
consistent with new spec change: https://github.com/whatwg/html/pull/2343
2. InvalidStateError exception when convertToBlob is calling on an
OffscreenCanvas
without rendering contexts. Spec change needs to be done later on.

Meanwhile, this CL also fixed crash bug in the corner case when convertToBlob
with webp image type fails.

BUG=659260, 563830

Review-Url: https://codereview.chromium.org/2695343002
Cr-Commit-Position: refs/heads/master@{#452935}
Committed:
https://chromium.googlesource.com/chromium/src/+/5ce8692f118a0f554fa98574be0c...
==========

[commit-bot: I haz the power, 2017-02-24 21:40:39]

Committed patchset #1 (id:1) as
https://chromium.googlesource.com/chromium/src/+/5ce8692f118a0f554fa98574be0c...