Add flag to enable antialiased clipping in HTML5 canvas

Add flag to enable antialiased clipping in HTML5 canvas

Here is the OWP tracking bug: https://code.google.com/p/chromium/issues/detail?id=422984
Here is the link to the entry on the feature dashboard: https://www.chromestatus.com/features/4871530282483712

Currently canvas clips are not antialiased which differs what what other
browsers are doing and what the users expect. This CL starts surfacing
the desired antialiased clipping behavior behind a flag
so developers can start assessing the capability.

This needs to land after the Blink CL: Plumb in flag to enable antialiased clipping in HTML 5 Canvas - https://codereview.chromium.org/652483003/

BUG=crbug.com/424291
BUG=crbug.com/422984

Committed: https://crrev.com/e25137bd1b720b121f4c365e08e9e18bb2cb9aab
Cr-Commit-Position: refs/heads/master@{#300261}

[robertphillips, 2014-10-13 15:14:39]

robertphillips@google.com changed reviewers:
+ ccameron@chromium.org

[robertphillips, 2014-10-13 15:16:05]

robertphillips@google.com changed reviewers:
+ jamesr@chromium.org

[robertphillips, 2014-10-13 15:17:02]

robertphillips@google.com changed reviewers:
+ jochen@chromium.org
- ccameron@chromium.org, jamesr@chromium.org

[jochen (gone - plz use gerrit), 2014-10-14 13:50:12]

lgtm with nit

you'll need a security review

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
File content/public/common/content_switches.h (right):

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
content/public/common/content_switches.h:92: CONTENT_EXPORT extern const char
kEnable2dCanvasClipAntialiasing[];
nit. no CONTENT_EXPORT

[Justin Novosad, 2014-10-14 14:21:49]

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

[Justin Novosad, 2014-10-14 14:21:50]

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
File content/public/common/content_switches.cc (right):

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
content/public/common/content_switches.cc:282: const char
kEnable2dCanvasClipAntialiasing[] = "enable-canvas-clip-aa";
Nit: command line flags that affect the 2d rendering context usually have
"-2d-canvas" in the name.

[robertphillips, 2014-10-16 13:33:23]

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
File content/public/common/content_switches.cc (right):

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
content/public/common/content_switches.cc:282: const char
kEnable2dCanvasClipAntialiasing[] = "enable-canvas-clip-aa";
On 2014/10/14 14:21:50, junov wrote:
> Nit: command line flags that affect the 2d rendering context usually have
> "-2d-canvas" in the name.

Done.

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
File content/public/common/content_switches.h (right):

https://codereview.chromium.org/650143002/diff/90001/content/public/common/co...
content/public/common/content_switches.h:92: CONTENT_EXPORT extern const char
kEnable2dCanvasClipAntialiasing[];
On 2014/10/14 13:50:12, jochen wrote:
> nit. no CONTENT_EXPORT

Done.

[Tom Sepez, 2014-10-16 16:34:30]

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

[Tom Sepez, 2014-10-16 16:34:31]

Messages LGTM.

[robertphillips, 2014-10-20 12:24:40]

The CQ bit was checked by robertphillips@google.com

[commit-bot: I haz the power, 2014-10-20 12:24:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/650143002/150001

[commit-bot: I haz the power, 2014-10-20 13:44:43]

Committed patchset #3 (id:150001)

[commit-bot: I haz the power, 2014-10-20 13:45:29]

Patchset 3 (id:??) landed as
https://crrev.com/e25137bd1b720b121f4c365e08e9e18bb2cb9aab
Cr-Commit-Position: refs/heads/master@{#300261}