Fixing crash during 2D canvas destruction

Fixing crash during 2D canvas destruction

This change unregisters the Canvas2DLayerBridge as a notification
client on the SkDeferedCanvas in order to prevent re-entry during
destruction.

BUG=453596
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=189582

[Justin Novosad, 2015-02-03 19:08:48]

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

[Justin Novosad, 2015-02-03 19:08:48]

PTAL

[Ken Russell (switch to Gerrit), 2015-02-04 01:21:19]

LGTM

[Ken Russell (switch to Gerrit), 2015-02-04 01:21:47]

P.S. A layout test which covers this code path would be great.

[Justin Novosad, 2015-02-04 06:15:40]

On 2015/02/04 01:21:47, Ken Russell wrote:
> P.S. A layout test which covers this code path would be great.
Unfortunately we are lacking repro steps for this.
It is hard to tell from the crash reports, but I think this issue may be related
to canvas teardown after a gpu context loss, in which case we are covered by:
virtual/gpu/fast/canvas/canvas-lost-gpu-context.html
That test currently suffers from mild flake, perhaps this will fix it.

[Justin Novosad, 2015-02-04 06:15:47]

The CQ bit was checked by junov@chromium.org

[commit-bot: I haz the power, 2015-02-04 06:16:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/885673005/20001

[commit-bot: I haz the power, 2015-02-04 08:43:34]

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

[commit-bot: I haz the power, 2015-02-04 08:43:35]

Try jobs failed on following builders:
  mac_blink_rel on tryserver.blink
(http://build.chromium.org/p/tryserver.blink/builders/mac_blink_rel/builds/41247)

[dshwang, 2015-02-04 13:32:05]

dongseong.hwang@intel.com changed reviewers:
+ dongseong.hwang@intel.com

[dshwang, 2015-02-04 13:32:06]

https://codereview.chromium.org/885673005/diff/20001/Source/platform/graphics...
File Source/platform/graphics/Canvas2DLayerBridge.cpp (right):

https://codereview.chromium.org/885673005/diff/20001/Source/platform/graphics...
Source/platform/graphics/Canvas2DLayerBridge.cpp:142:
m_canvas->setNotificationClient(0);
The patch demonstrates that the destructor is called without beginDestruction().
It looks like the root bug still exist.

[Justin Novosad, 2015-02-05 18:11:27]

The CQ bit was checked by junov@chromium.org

[commit-bot: I haz the power, 2015-02-05 18:12:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/885673005/20001

[commit-bot: I haz the power, 2015-02-05 19:07:02]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=189582