commit a81779b51a943a37acf879c458d9c84fade53251
author varkha <varkha@chromium.org> Tue Jun 28 01:39:13 2016
committer Commit bot <commit-bot@chromium.org> Tue Jun 28 01:41:13 2016
tree 9c3e62cdda0d6bbf24f38278a3af60e4f368aa10
parent 2840f95e176111e2f468382a51256dc0a34ec547

[ash-md] Adds UMA items count and selection depth for Alt+Tab

Adds Ash.WindowCycleController.Items UMA histogram that records how
many windows are included in Alt+Tab enumeration. The count is captured
when Alt+Tab is pressed.

Adds Ash.WindowCycleController.SelectionDepth UMA histogram that records
how often users finish Alt+Tab selection on a window that is N-th in MRU
order. Selecting a window that is already currently active (top in MRU
order) records 1.

BUG=621562

Review-Url: https://codereview.chromium.org/2096063002
Cr-Commit-Position: refs/heads/master@{#402365}