Remove Label::PaintText overrides.

Remove Label::PaintText overrides.

This is simple cleanup in preparation for a Label rewrite.
These overrides were supplying an extra gfx::Canvas flag.
Instead, add an explicit label flag for NO_SUBPIXEL_RENDERING.
Update some callers and the unit test.

TODO(followup): Update more Label::SetBackgroundColor callers.

BUG=240037
TEST=No exit warning or sticky keys label rendering changes.
R=sky@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278213

[msw, 2014-06-17 23:25:49]

Hey Scott, please take a look; thanks!

[sky, 2014-06-18 03:16:30]

https://codereview.chromium.org/341713002/diff/40001/ash/accelerators/exit_wa...
File ash/accelerators/exit_warning_handler.cc (right):

https://codereview.chromium.org/341713002/diff/40001/ash/accelerators/exit_wa...
ash/accelerators/exit_warning_handler.cc:67:
label->SetBackgroundColor(SK_ColorTRANSPARENT);
Having transparent mean no subpixel rendering seems like something that could
easily change. Can we have a real API for explicitly turning off subpixel
rendering instead?

[msw, 2014-06-18 04:34:29]

Please take another look; thanks!

https://codereview.chromium.org/341713002/diff/40001/ash/accelerators/exit_wa...
File ash/accelerators/exit_warning_handler.cc (right):

https://codereview.chromium.org/341713002/diff/40001/ash/accelerators/exit_wa...
ash/accelerators/exit_warning_handler.cc:67:
label->SetBackgroundColor(SK_ColorTRANSPARENT);
On 2014/06/18 03:16:29, sky wrote:
> Having transparent mean no subpixel rendering seems like something that could
> easily change. Can we have a real API for explicitly turning off subpixel
> rendering instead?

AFAIK, there's no way to use subpixel rendering with a partially transparent
background, and there are many other Label users that do something similar. That
said, the background color isn't actually drawn in the general case (it's only
used for assessing readability) and I think an explicit flag is a decent idea.
I've added that alternate way to disable subpixel rendering, fixed the Textfield
usage, and updated the unit test; perhaps I'll audit and cleanup the remaining
SetBackgroundColor call sites later.

[sky, 2014-06-18 16:51:38]

LGTM

[msw, 2014-06-18 16:53:33]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2014-06-18 16:54:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/msw@chromium.org/341713002/60001

[commit-bot: I haz the power, 2014-06-18 17:04:08]

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

[commit-bot: I haz the power, 2014-06-18 17:04:09]

Try jobs failed on following builders:
  ios_rel_device_ninja on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/ios_rel_device_ninja/...)

[msw, 2014-06-18 17:33:16]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2014-06-18 17:33:53]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/msw@chromium.org/341713002/80001

[commit-bot: I haz the power, 2014-06-19 01:09:41]

Change committed as 278213