Fix a regression caused by my change to make the first run bubble window display as an inactive win…

Fix a regression caused by my change to make the first run bubble window display as an inactive window.

The expectation is that we should dismiss the bubble on activities like mouse down, touch down, on the anchor
window as well.

The FirstRunBubbleCloser class now observes the native view instead of the root view as the latter does not work
if we have mouse and touch events on the RWHVA.

BUG=555416
TEST=Covered by tests FirstRunBubbleTest.CloseBubbleOnMouseDownEvent and FirstRunBubbleTest.CloseBubbleOnTouchDownEvent

Committed: https://crrev.com/50a8b1f1eb5cf75b2fc756389cc783d33cd0934c
Cr-Commit-Position: refs/heads/master@{#359902}

[ananta, 2015-11-14 02:53:49]

ananta@chromium.org changed reviewers:
+ sky@chromium.org

[sky, 2015-11-14 15:32:25]

LGTM

[ananta, 2015-11-16 19:57:27]

The CQ bit was checked by ananta@chromium.org

[commit-bot: I haz the power, 2015-11-16 19:58:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1443253004/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1443253004/1

[commit-bot: I haz the power, 2015-11-16 20:38:15]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-16 20:39:38]

Patchset 1 (id:??) landed as
https://crrev.com/50a8b1f1eb5cf75b2fc756389cc783d33cd0934c
Cr-Commit-Position: refs/heads/master@{#359902}