Make OffscreenCanvas histogram thread safe

Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

A layout test has been added to make sure that the test doesn't crash.

BUG=663916
Committed: https://crrev.com/e9ccbda7993554fbdeab8810be5e4ac3ac669f8d
Cr-Commit-Position: refs/heads/master@{#432333}

[xidachen, 2016-11-15 19:13:24]

Description was changed from

==========
Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

BUG=663916
==========

to

==========
Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

A layout test has been added to make sure that the test doesn't crash.

BUG=663916
==========

[xidachen, 2016-11-15 19:13:24]

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

[xidachen, 2016-11-15 19:13:31]

PTAL

[Justin Novosad, 2016-11-15 19:44:55]

https://codereview.chromium.org/2502853003/diff/1/third_party/WebKit/LayoutTe...
File
third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-multiple-worker-commit.html
(right):

https://codereview.chromium.org/2502853003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-multiple-worker-commit.html:12:
<script id="myWorker2" type="text/worker">
No need for two identical worker scripts. You should just create worker1 and
worker2 from the same script.

[xidachen, 2016-11-15 19:49:02]

https://codereview.chromium.org/2502853003/diff/1/third_party/WebKit/LayoutTe...
File
third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-multiple-worker-commit.html
(right):

https://codereview.chromium.org/2502853003/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-multiple-worker-commit.html:12:
<script id="myWorker2" type="text/worker">
On 2016/11/15 19:44:55, Justin Novosad wrote:
> No need for two identical worker scripts. You should just create worker1 and
> worker2 from the same script.

Done.

[Justin Novosad, 2016-11-15 20:24:58]

lgtm

https://codereview.chromium.org/2502853003/diff/20001/third_party/WebKit/Layo...
File
third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-multiple-worker-commit.html
(right):

https://codereview.chromium.org/2502853003/diff/20001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/fast/canvas/OffscreenCanvas-multiple-worker-commit.html:28:
var worker1 = makeWorker(document.getElementById("myWorker").textContent);
Nit: no need for an argument for makeWorker because it always loads the same
script.

[xidachen, 2016-11-15 20:51:28]

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

[commit-bot: I haz the power, 2016-11-15 20:51:44]

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, 2016-11-15 21:05:13]

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

[commit-bot: I haz the power, 2016-11-15 21:05:14]

Dry run: Try jobs failed on following builders:
  cast_shell_linux on master.tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linu...)

[xidachen, 2016-11-16 00:54:13]

The CQ bit was checked by xidachen@chromium.org

[xidachen, 2016-11-16 00:54:13]

The patchset sent to the CQ was uploaded after l-g-t-m from junov@chromium.org
Link to the patchset: https://codereview.chromium.org/2502853003/#ps40001
(title: "nits")

[commit-bot: I haz the power, 2016-11-16 00:54:49]

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, 2016-11-16 01:22:15]

Description was changed from

==========
Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

A layout test has been added to make sure that the test doesn't crash.

BUG=663916
==========

to

==========
Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

A layout test has been added to make sure that the test doesn't crash.

BUG=663916
==========

[commit-bot: I haz the power, 2016-11-16 01:22:16]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-11-16 01:25:51]

Description was changed from

==========
Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

A layout test has been added to make sure that the test doesn't crash.

BUG=663916
==========

to

==========
Make OffscreenCanvas histogram thread safe

In OffscreenCanvasFrameDispatcherImpl::dispatchFrame, we have a timer
histogram at the end of this function which uses DEFINE_STATIC_LOCAL. This
is not thread safe in the cases where multiple worker commit at the same
time. This CL makes the timer histogram thread safe.

A layout test has been added to make sure that the test doesn't crash.

BUG=663916

Committed: https://crrev.com/e9ccbda7993554fbdeab8810be5e4ac3ac669f8d
Cr-Commit-Position: refs/heads/master@{#432333}
==========

[commit-bot: I haz the power, 2016-11-16 01:25:52]

Patchset 3 (id:??) landed as
https://crrev.com/e9ccbda7993554fbdeab8810be5e4ac3ac669f8d
Cr-Commit-Position: refs/heads/master@{#432333}