ozone: evdev: Fix possibility of stuck mouse buttons

ozone: evdev: Fix possibility of stuck mouse buttons

Same as previous fix, but for mouse buttons.

The SYN_DROPPED part is N/A because that is handled by libevdev.

BUG=463002
TEST=Tested unplug by unplugging mouse with left button held.
  Left mouse button gets properly released rather than being stuck.
  (NB: Could not reproduce without adding a delay to expose the race).

Committed: https://crrev.com/ba7886ae1f916481419df25f923307df1e191579
Cr-Commit-Position: refs/heads/master@{#319699}

[spang, 2015-03-07 00:35:08]

spang@chromium.org changed reviewers:
+ kpschoedel@chromium.org

[kpschoedel, 2015-03-07 02:29:39]

Same LGTM as previous fix, but for mouse buttons.

[spang, 2015-03-09 17:48:12]

The CQ bit was checked by spang@chromium.org

[commit-bot: I haz the power, 2015-03-09 17:49:09]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/983213003/1

[commit-bot: I haz the power, 2015-03-09 18:40:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-09 18:41:26]

Patchset 1 (id:??) landed as
https://crrev.com/ba7886ae1f916481419df25f923307df1e191579
Cr-Commit-Position: refs/heads/master@{#319699}