Turning on clip anti-aliasing by default in Chrome.

Removing run-time flag "--enable-2d-canvas-clip-aa".
Setting the default behavior to anti-aliasing 2D canvas clips.
Adding run-time flag "--disable-2d-canvas-clip-aa".

BUG=424291
Committed: https://crrev.com/20ebca037955834a66e956a2dae71daef7884d25
Cr-Commit-Position: refs/heads/master@{#421198}

[zakerinasab, 2016-09-21 19:23:55]

Description was changed from

==========
Turning on clip anti-aliasing by default in Chrome.

BUG=424291
==========

to

==========
Removing run-time flag "--enable-2d-canvas-clip-aa". 
Setting the default behavior to anti-aliasing 2D canvas clips.
Adding run-time flag "--disable-2d-canvas-clip-aa". 


BUG=424291
==========

[zakerinasab, 2016-09-21 21:06:05]

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

[zakerinasab, 2016-09-21 21:06:05]

New patch is submitted. This patch activates anti-aliasing for canvas 2d clips
by default, and also allows the feature to be turned off using
--disable-2d-canvas-clip-aa flag. A harness test layout is provided too.

[Justin Novosad, 2016-09-21 21:27:02]

https://codereview.chromium.org/2359843003/diff/40001/content/public/common/w...
File content/public/common/web_preferences.cc (right):

https://codereview.chromium.org/2359843003/diff/40001/content/public/common/w...
content/public/common/web_preferences.cc:114:
antialiased_clips_2d_canvas_disabled(false),
instead of changing the name, initialize this to true

https://codereview.chromium.org/2359843003/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/frame/Settings.in (right):

https://codereview.chromium.org/2359843003/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/frame/Settings.in:90:
antialiasedClips2dCanvasDisabled initial=false
This is not correct. We do not do inverted logic for flags.  Keep 'Enabled' like
before, just change the default to true.

[zakerinasab, 2016-09-22 14:10:23]

On 2016/09/21 21:27:02, Justin Novosad wrote:
>
https://codereview.chromium.org/2359843003/diff/40001/content/public/common/w...
> File content/public/common/web_preferences.cc (right):
> 
>
https://codereview.chromium.org/2359843003/diff/40001/content/public/common/w...
> content/public/common/web_preferences.cc:114:
> antialiased_clips_2d_canvas_disabled(false),
> instead of changing the name, initialize this to true
> 
>
https://codereview.chromium.org/2359843003/diff/40001/third_party/WebKit/Sour...
> File third_party/WebKit/Source/core/frame/Settings.in (right):
> 
>
https://codereview.chromium.org/2359843003/diff/40001/third_party/WebKit/Sour...
> third_party/WebKit/Source/core/frame/Settings.in:90:
> antialiasedClips2dCanvasDisabled initial=false
> This is not correct. We do not do inverted logic for flags.  Keep 'Enabled'
like
> before, just change the default to true.

The reasoning behind this was to allow developers to use Chromium without AA for
canvas clips so they can test if an expected or unexpected behavior has anything
to do with this CL, which is not possible If we turn the AA flag on by default
and do not provide any option to disable it.

[xlai (Olivia), 2016-09-22 14:11:35]

https://codereview.chromium.org/2359843003/diff/40001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/frame/Settings.in (right):

https://codereview.chromium.org/2359843003/diff/40001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/frame/Settings.in:90:
antialiasedClips2dCanvasDisabled initial=false
On 2016/09/21 21:27:02, Justin Novosad wrote:
> This is not correct. We do not do inverted logic for flags.  Keep 'Enabled'
like
> before, just change the default to true.

I assume you want to enforce antialiasedClips to be enabled by default.
According to the previous comment, we want to keep the
antialiazedClips2dCanvasEnabled flag name unchanged. Then if we set this flag to
be true, what happened if users append this flag in command line? There would be
no effect (you're turning on something that is already on by default).

I checked chrome://flags and couldn't find this flag available to be modified in
GUI. It seems that it can only be passed on in command line.

[zakerinasab, 2016-09-22 19:00:19]

New patch submitted.

[Justin Novosad, 2016-09-22 19:15:18]

https://codereview.chromium.org/2359843003/diff/60001/third_party/WebKit/Layo...
File
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html
(right):

https://codereview.chromium.org/2359843003/diff/60001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html:29:
// junction of the third and fourth segments of the path.
You should check multiple points. you never know how this might regress in the
future.

https://codereview.chromium.org/2359843003/diff/60001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html:36:
}, 'canvas-2d-clip-anti-aliasing should not return any error');
The description you put here should describe what is being tested. "Verifies
that a stroke inside a clip of the same path displays correctly. Some sides of
the shape may be clipped-out if stroking is anti-aliased but not clipping, or if
clipping it is not properly aligned."

[zakerinasab, 2016-09-22 19:54:35]

New patch submitted.

[Justin Novosad, 2016-09-22 19:56:48]

https://codereview.chromium.org/2359843003/diff/80001/third_party/WebKit/Layo...
File
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html
(right):

https://codereview.chromium.org/2359843003/diff/80001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html:51:
}, 'canvas-2d-clip-anti-aliasing should not return any error');
This string needs to be more descriptive.  What is tested?

[zakerinasab, 2016-09-22 20:09:24]

New patch submitted.

https://codereview.chromium.org/2359843003/diff/80001/third_party/WebKit/Layo...
File
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html
(right):

https://codereview.chromium.org/2359843003/diff/80001/third_party/WebKit/Layo...
third_party/WebKit/LayoutTests/fast/canvas/canvas-2d-clip-anti-aliasing.html:51:
}, 'canvas-2d-clip-anti-aliasing should not return any error');
On 2016/09/22 19:56:48, Justin Novosad wrote:
> This string needs to be more descriptive.  What is tested?

Done.

[Justin Novosad, 2016-09-22 20:42:33]

lgtm for third_part/WebKit/*

[zakerinasab, 2016-09-22 20:57:20]

On 2016/09/22 20:42:33, Justin Novosad wrote:
> lgtm for third_part/WebKit/*

+ccameron@chromium.org for content/browser/renderer_host/
+dcheng@chromium.org for content/public/common/
+esprehn@chromium.org for content/renderer/

[zakerinasab, 2016-09-22 20:58:30]

zakerinasab@chromium.org changed reviewers:
+ ccameron@chromium.org, dcheng@chromium.org, esprehn@chromium.org

[zakerinasab, 2016-09-22 20:59:34]

+ccameron@chromium.org for content/browser/renderer_host/
+dcheng@chromium.org for content/public/common/
+esprehn@chromium.org for content/renderer/

[ccameron, 2016-09-22 21:00:16]

lgtm

[dcheng, 2016-09-22 21:25:01]

I don't think I'm an owner for any files in this CL?

[zakerinasab, 2016-09-23 13:36:14]

zakerinasab@chromium.org changed reviewers:
+ pfeldman@chromium.org
- dcheng@chromium.org

[zakerinasab, 2016-09-23 13:37:07]

+pfeldman@chromium.org, please take a look at content/.

[pfeldman, 2016-09-26 23:13:04]

lgtm

[zakerinasab1, 2016-09-27 13:05:48]

The CQ bit was checked by zakerinasab@google.com

[commit-bot: I haz the power, 2016-09-27 13:06:06]

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, 2016-09-27 14:22:58]

Description was changed from

==========
Removing run-time flag "--enable-2d-canvas-clip-aa". 
Setting the default behavior to anti-aliasing 2D canvas clips.
Adding run-time flag "--disable-2d-canvas-clip-aa". 


BUG=424291
==========

to

==========
Removing run-time flag "--enable-2d-canvas-clip-aa". 
Setting the default behavior to anti-aliasing 2D canvas clips.
Adding run-time flag "--disable-2d-canvas-clip-aa". 


BUG=424291
==========

[commit-bot: I haz the power, 2016-09-27 14:22:59]

Committed patchset #6 (id:100001)

[commit-bot: I haz the power, 2016-09-27 14:24:59]

Description was changed from

==========
Removing run-time flag "--enable-2d-canvas-clip-aa". 
Setting the default behavior to anti-aliasing 2D canvas clips.
Adding run-time flag "--disable-2d-canvas-clip-aa". 


BUG=424291
==========

to

==========
Removing run-time flag "--enable-2d-canvas-clip-aa".
Setting the default behavior to anti-aliasing 2D canvas clips.
Adding run-time flag "--disable-2d-canvas-clip-aa".

BUG=424291

Committed: https://crrev.com/20ebca037955834a66e956a2dae71daef7884d25
Cr-Commit-Position: refs/heads/master@{#421198}
==========

[commit-bot: I haz the power, 2016-09-27 14:25:00]

Patchset 6 (id:??) landed as
https://crrev.com/20ebca037955834a66e956a2dae71daef7884d25
Cr-Commit-Position: refs/heads/master@{#421198}