Null-check Compositor() in PaintLayer

Null-check Compositor() in PaintLayer

BUG=712552
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2844513004
Cr-Commit-Position: refs/heads/master@{#467222}
Committed: https://chromium.googlesource.com/chromium/src/+/3b9d4808c5fd97ac53ba145ccdc2623cd0e551ea

[chrishtr, 2017-04-25 22:35:18]

Description was changed from

==========
none


none


none


none

BUG=
==========

to

==========
none


none


none


none

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[chrishtr, 2017-04-25 22:36:18]

Description was changed from

==========
none


none


none


none

BUG=
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Null-check Compositor() in PaintLayer

BUG=712552
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

[chrishtr, 2017-04-25 22:38:49]

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

[chrishtr, 2017-04-25 22:39:00]

chrishtr@chromium.org changed reviewers:
+ wkorman@chromium.org

[commit-bot: I haz the power, 2017-04-25 22:39:17]

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, 2017-04-26 00:39:21]

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

[commit-bot: I haz the power, 2017-04-26 00:39:21]

Dry run: This issue passed the CQ dry run.

[wkorman, 2017-04-26 01:04:36]

lgtm

Re: how Compositor() could return nullptr, it looks like the only two possible
causes are either (1) document has no LayoutView, or (2)
LayoutView::WillBeDestroyed() was called.

I am not sure when (1) would happen other than perhaps during
initialization/setup.

(2), how could we call Compositor() after WillBeDestroyed(), maybe if we have
observers/event listeners responding to other activity and we haven't yet
actually destroyed it, or, we're destroyed but we process the rest of the
lifecycle following.

Anyway, I was exploring in case there was something else we could do vs
null-checking, like early-out on document lifecycle or otherwise, but it's
across multiple methods anyway. This seems totally reasonable.

https://codereview.chromium.org/2844513004/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayer.cpp (right):

https://codereview.chromium.org/2844513004/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayer.cpp:243: if
(HasCompositedLayerMapping()) {
It looks like we used to only do this if change_type == kCanvasContextChanged.
Is it ok to move it out and do it regardless of what change_type is?

[chrishtr, 2017-04-26 01:09:38]

The CQ bit was checked by chrishtr@chromium.org

[chrishtr, 2017-04-26 01:09:39]

https://codereview.chromium.org/2844513004/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/paint/PaintLayer.cpp (right):

https://codereview.chromium.org/2844513004/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/paint/PaintLayer.cpp:243: if
(HasCompositedLayerMapping()) {
On 2017/04/26 at 01:04:36, wkorman wrote:
> It looks like we used to only do this if change_type == kCanvasContextChanged.
Is it ok to move it out and do it regardless of what change_type is?

Oh, that was not intended. Fixed.

[chrishtr, 2017-04-26 01:09:39]

The patchset sent to the CQ was uploaded after l-g-t-m from wkorman@chromium.org
Link to the patchset: https://codereview.chromium.org/2844513004/#ps60001
(title: "none")

[commit-bot: I haz the power, 2017-04-26 01:10:12]

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, 2017-04-26 03:11:17]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1493168978354110,
"parent_rev": "1e82a4e0332697a6e0115de726ca801f0ccf54ce", "commit_rev":
"3b9d4808c5fd97ac53ba145ccdc2623cd0e551ea"}

[commit-bot: I haz the power, 2017-04-26 03:11:51]

Description was changed from

==========
Null-check Compositor() in PaintLayer

BUG=712552
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
==========

to

==========
Null-check Compositor() in PaintLayer

BUG=712552
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2844513004
Cr-Commit-Position: refs/heads/master@{#467222}
Committed:
https://chromium.googlesource.com/chromium/src/+/3b9d4808c5fd97ac53ba145ccdc2...
==========

[commit-bot: I haz the power, 2017-04-26 03:11:53]

Committed patchset #4 (id:60001) as
https://chromium.googlesource.com/chromium/src/+/3b9d4808c5fd97ac53ba145ccdc2...