Fix crash in canvas.toBlob caused by allocation failure

Fix crash and potential crashes caused by ImageBuffer allocation failure.

This CL add null ptr checks in a few places that need them.

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel

Committed: https://crrev.com/9d280866e11c2c038005452c8d14fb3ffa91ac2c
Cr-Commit-Position: refs/heads/master@{#418563}

[Justin Novosad, 2016-09-13 16:37:06]

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

[commit-bot: I haz the power, 2016-09-13 16:37:18]

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

[Justin Novosad, 2016-09-13 16:37:42]

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

[Justin Novosad, 2016-09-13 16:37:42]

PTAL

[xidachen, 2016-09-13 16:53:03]

Please also null check:
WebGLRenderingContextBase.cpp:4266

https://codereview.chromium.org/2335263002/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp (right):

https://codereview.chromium.org/2335263002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp:307: if
(m_context->is2d() && buffer()->isAccelerated()
should we worry about this call site?

https://codereview.chromium.org/2335263002/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp:326: if
(m_pendingRenderingModeSwitch && !buffer()->isAccelerated()) {
This one as well?

[Justin Novosad, 2016-09-13 17:10:07]

Description was changed from

==========
Fix crash in canvas.toBlob caused by allocation failure

BUG=644644
==========

to

==========
Fix crash in canvas.toBlob caused by allocation failure

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[Justin Novosad, 2016-09-13 17:10:33]

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

[commit-bot: I haz the power, 2016-09-13 17:10:51]

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

[Justin Novosad, 2016-09-13 17:11:31]

Description was changed from

==========
Fix crash in canvas.toBlob caused by allocation failure

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Fix crash and potential crashes caused by ImageBuffer allocation failure.

This CL add null ptr checks in a few places that need them.

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[Justin Novosad, 2016-09-13 17:11:42]

Done.

[xidachen, 2016-09-13 17:16:18]

lgtm

[Justin Novosad, 2016-09-13 17:19:52]

The CQ bit was unchecked by junov@chromium.org

[Justin Novosad, 2016-09-13 17:19:57]

The CQ bit was checked by junov@chromium.org

[commit-bot: I haz the power, 2016-09-13 17:20:24]

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, 2016-09-13 17:27:57]

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

[commit-bot: I haz the power, 2016-09-13 17:27:58]

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

[xidachen, 2016-09-13 17:30:12]

On 2016/09/13 17:27:58, commit-bot: I haz the power wrote:
> Try jobs failed on following builders:
>   chromium_presubmit on master.tryserver.chromium.linux (JOB_FAILED,
>
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

I am not the OWNER, you may need senorblanco@'s L-G-T-M

[xidachen, 2016-09-13 17:31:37]

xidachen@chromium.org changed reviewers:
+ senorblanco@chromium.org

[xidachen, 2016-09-13 17:31:37]

+senorblanco@: needs L-G-T-M from an OWNER of modules/

[Justin Novosad, 2016-09-13 17:32:29]

junov@chromium.org changed reviewers:
+ kbr@chromium.org
- senorblanco@chromium.org

[Justin Novosad, 2016-09-13 17:32:29]

+ kbr for webgl OWNER

[Ken Russell (switch to Gerrit), 2016-09-13 17:44:53]

Seems fine. LGTM

[Justin Novosad, 2016-09-13 17:45:56]

The CQ bit was checked by junov@chromium.org

[commit-bot: I haz the power, 2016-09-13 17:46:23]

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, 2016-09-13 20:52:04]

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

[commit-bot: I haz the power, 2016-09-13 20:52:05]

Try jobs failed on following builders:
  win_chromium_rel_ng on master.tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win_chromium_rel_...)

[Stephen White, 2016-09-13 22:09:17]

senorblanco@chromium.org changed reviewers:
+ senorblanco@chromium.org

[Stephen White, 2016-09-13 22:09:18]

LGTM

[xidachen, 2016-09-14 01:13:22]

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

[commit-bot: I haz the power, 2016-09-14 01:13:57]

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, 2016-09-14 02:43:02]

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

[commit-bot: I haz the power, 2016-09-14 02:43:03]

Dry run: This issue passed the CQ dry run.

[xidachen, 2016-09-14 14:54:07]

The CQ bit was checked by xidachen@chromium.org

[commit-bot: I haz the power, 2016-09-14 14:54:23]

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, 2016-09-14 14:59:23]

Description was changed from

==========
Fix crash and potential crashes caused by ImageBuffer allocation failure.

This CL add null ptr checks in a few places that need them.

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Fix crash and potential crashes caused by ImageBuffer allocation failure.

This CL add null ptr checks in a few places that need them.

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

[commit-bot: I haz the power, 2016-09-14 14:59:25]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-14 15:00:39]

Description was changed from

==========
Fix crash and potential crashes caused by ImageBuffer allocation failure.

This CL add null ptr checks in a few places that need them.

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel
==========

to

==========
Fix crash and potential crashes caused by ImageBuffer allocation failure.

This CL add null ptr checks in a few places that need them.

BUG=644644
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel

Committed: https://crrev.com/9d280866e11c2c038005452c8d14fb3ffa91ac2c
Cr-Commit-Position: refs/heads/master@{#418563}
==========

[commit-bot: I haz the power, 2016-09-14 15:00:41]

Patchset 2 (id:??) landed as
https://crrev.com/9d280866e11c2c038005452c8d14fb3ffa91ac2c
Cr-Commit-Position: refs/heads/master@{#418563}