[OSX] Handle PermissionBubble coalescing

[OSX] Handle PermissionBubble coalescing

PermissionBubbleCocoa::CanAcceptRequestUpdate controls request
coalescing. This change allows requests to be added to an existing
permission bubble unless the user has moused over the bubble.

BUG=452931
Committed: https://crrev.com/2f435c4d5e6356e9a4506d4c725ffad3eb7aa16d
Cr-Commit-Position: refs/heads/master@{#327365}

[groby-ooo-7-16, 2015-04-23 05:44:15]

groby@chromium.org changed reviewers:
+ felt@chromium.org

[groby-ooo-7-16, 2015-04-23 05:45:00]

PTAL

Implements the equivalent of the Views code. This is a good-faith
implementation, since the manager only uses this when cancelling requests right
now - I have no idea how to trigger that.

[felt, 2015-04-24 15:57:59]

lgtm... as a basic sniff test. I don't know enough about Mac to know if it
really works, I just have to take your word for it. ;)

[groby-ooo-7-16, 2015-04-28 20:30:36]

On 2015/04/24 15:57:59, felt wrote:
> lgtm... as a basic sniff test. I don't know enough about Mac to know if it
> really works, I just have to take your word for it. ;)

So no way to trigger this properly... Oh well. It works in theory on your side,
it works in theory on my side. What could possibly happen :)

Please ping me when you update PermissionBubbleManager to use this, in case we
run into trouble. Meanwhile, I'll commit this.

[groby-ooo-7-16, 2015-04-28 20:30:41]

The CQ bit was checked by groby@chromium.org

[commit-bot: I haz the power, 2015-04-28 20:30:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/895363007/1

[commit-bot: I haz the power, 2015-04-28 21:35:47]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-28 21:36:30]

Patchset 1 (id:??) landed as
https://crrev.com/2f435c4d5e6356e9a4506d4c725ffad3eb7aa16d
Cr-Commit-Position: refs/heads/master@{#327365}