Fixes bug where Env/RootWindow would cache the wrong button

Fixes bug where Env/RootWindow would cache the wrong button
state. Specifically on a release they would cache MouseEvent::flags(),
which includes the buttons that were released. I've plumbed through
the ability to identify the button that was pressed/released.

I'll implement windows in a separate patch.

BUG=140102
TEST=none
R=ben@chromium.org, sadrul@chromium.org


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=151533

[Ben Goodger (Google), 2012-08-14 01:35:34]

lgtm

[sadrul, 2012-08-14 01:47:04]

LGTM

[commit-bot: I haz the power, 2012-08-14 14:58:11]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sky@chromium.org/10830293/2001

[commit-bot: I haz the power, 2012-08-14 14:58:13]

Failed to apply patch for ui/base/event.h:
While running patch -p1 --forward --force;
patching file ui/base/event.h
Hunk #3 FAILED at 221.
1 out of 3 hunks FAILED -- saving rejects to file ui/base/event.h.rej

[commit-bot: I haz the power, 2012-08-14 17:04:05]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sky@chromium.org/10830293/1009

[commit-bot: I haz the power, 2012-08-14 19:17:36]

Change committed as 151533