commit 1c9d363ad3a2a05b37be0fe23a2981ddb65e53a1
author Maggie Chen <magchen@chromium.org> Thu Mar 14 15:49:39 2019
committer Commit Bot <commit-bot@chromium.org> Thu Mar 14 15:49:39 2019
tree d9f6494701c62902999c3dac70b0651be32f1c81
parent 8d9708724008a29b9749068a574d73cdc3f08753

Add UMA histograms for DC layer overlay.

1. Record Underlay vs. Overlay.
2. Record Full screen mode vs. Non Full screen (Windows) mode.
3. Record zero damage rect vs. non-zero damage rect for overlay.
4. Record zero damage rect, non-zero damage rect without occluding damage,
   and non-zero damage rect with occluding damage only, and non-zero
   damage rect with both damages for underlay.

Bug:868561

Change-Id: Ia734e6a6427b5d67ab559482b7f8f0b58d1aa18b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1511704
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Commit-Queue: Maggie Chen <magchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#640768}