Expose double-tap platform support via ui::GestureConfiguration

Expose double-tap platform support via ui::GestureConfiguration

Propagate platform support for double-tap gestures from
ui::GestureConfiguration to GestureProvider::Config, ensuring consistent
platform-specific double-tap behavior.

BUG=425586, 325506
Committed: https://crrev.com/d823c1b21de57472e1bd52f7a3d9c7c23239b3b9
Cr-Commit-Position: refs/heads/master@{#312725}

[jdduke (slow), 2015-01-22 19:50:15]

jdduke@chromium.org changed reviewers:
+ tdresser@chromium.org

[jdduke (slow), 2015-01-22 19:50:15]

tdresser@: PTAL, thanks.

[tdresser, 2015-01-22 20:24:19]

On 2015/01/22 19:50:15, jdduke wrote:
> tdresser@: PTAL, thanks.

We should probably add some tests for this configuration pipeline at some point.
That doesn't need to block this patch though.

LGTM.

[jdduke (slow), 2015-01-22 20:24:49]

On 2015/01/22 20:24:19, tdresser wrote:
> On 2015/01/22 19:50:15, jdduke wrote:
> > tdresser@: PTAL, thanks.
> 
> We should probably add some tests for this configuration pipeline at some
point.
> That doesn't need to block this patch though.

Agreed.

> 
> LGTM.

[jdduke (slow), 2015-01-22 20:25:51]

The CQ bit was checked by jdduke@chromium.org

[commit-bot: I haz the power, 2015-01-22 20:26:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/868823002/20001

[commit-bot: I haz the power, 2015-01-23 00:48:27]

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

[commit-bot: I haz the power, 2015-01-23 00:48:28]

Try jobs failed on following builders:
  win_gpu on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu/builds/11...)

[jdduke (slow), 2015-01-23 00:55:04]

The CQ bit was checked by jdduke@chromium.org

[commit-bot: I haz the power, 2015-01-23 00:57:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/868823002/20001

[commit-bot: I haz the power, 2015-01-23 01:18:30]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-01-23 01:19:17]

Patchset 2 (id:??) landed as
https://crrev.com/d823c1b21de57472e1bd52f7a3d9c7c23239b3b9
Cr-Commit-Position: refs/heads/master@{#312725}