The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7468905cf4b9704360e3556e3b54347ee6df77d9

commit 7468905cf4b9704360e3556e3b54347ee6df77d9
Author: akaba <akaba@google.com>
Date: Mon Jul 23 23:47:40 2018

UMA for SurfaceManager

This CL adds the 3 following histograms:

1) logs the number of alive surfaces after each surface garbage
collection in Viz.

2) logs the number of temporary references after each surface garbage
collection in Viz.

3) logs the distance between a surface returned by SurfaceManager::GetLatestInFlightSurface
and the primary_surface_id passed in.

Bug:  866113 
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel
Change-Id: I644c5005ba1a0997956a75083f8b25bd8a5f5abc
Reviewed-on: https://chromium-review.googlesource.com/1142591
Commit-Queue: Andre Kaba <akaba@google.com>
Reviewed-by: Sadrul Chowdhury <sadrul@chromium.org>
Reviewed-by: Saman Sami <samans@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Fady Samuel <fsamuel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577340}
[modify] https://crrev.com/7468905cf4b9704360e3556e3b54347ee6df77d9/components/viz/common/surfaces/surface_id.cc
[modify] https://crrev.com/7468905cf4b9704360e3556e3b54347ee6df77d9/components/viz/common/surfaces/surface_id.h
[modify] https://crrev.com/7468905cf4b9704360e3556e3b54347ee6df77d9/components/viz/service/display/surface_aggregator.cc
[modify] https://crrev.com/7468905cf4b9704360e3556e3b54347ee6df77d9/components/viz/service/surfaces/surface_manager.cc
[modify] https://crrev.com/7468905cf4b9704360e3556e3b54347ee6df77d9/tools/metrics/histograms/histograms.xml