The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f769f364f71068930d971dafb86dc1c5f298a8a7

commit f769f364f71068930d971dafb86dc1c5f298a8a7
Author: shaktisahu <shaktisahu@chromium.org>
Date: Tue Sep 13 22:01:29 2016

Adding UMA stats for Blimp Client

Added metrics for tracking when blimp is supported, blimp is connected,
blimp tabs are shown or hidden, size of commit messages.

BUG= 645545 

Review-Url: https://codereview.chromium.org/2326913004
Cr-Commit-Position: refs/heads/master@{#418386}

[modify] https://crrev.com/f769f364f71068930d971dafb86dc1c5f298a8a7/blimp/client/core/blimp_client_context_impl.cc
[modify] https://crrev.com/f769f364f71068930d971dafb86dc1c5f298a8a7/blimp/client/core/compositor/blimp_compositor.cc
[modify] https://crrev.com/f769f364f71068930d971dafb86dc1c5f298a8a7/blimp/client/core/contents/blimp_contents_impl.cc
[modify] https://crrev.com/f769f364f71068930d971dafb86dc1c5f298a8a7/blimp/client/core/dummy_blimp_client_context.cc
[modify] https://crrev.com/f769f364f71068930d971dafb86dc1c5f298a8a7/tools/metrics/histograms/histograms.xml