The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/5d97a507995f0a7945123b6d78c566c27567264a

commit 5d97a507995f0a7945123b6d78c566c27567264a
Author: melandory <melandory@chromium.org>
Date: Fri Oct 28 07:35:22 2016

Demonstrates example when GetTotalCountsForPrefix returns ture for the suffix.

BUG= 659977 

Review-Url: https://codereview.chromium.org/2451213003
Cr-Commit-Position: refs/heads/master@{#428307}

[modify] https://crrev.com/5d97a507995f0a7945123b6d78c566c27567264a/base/test/histogram_tester_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/63e22b6fcb629ebccc0f257de04bc8e7f4ef247c

commit 63e22b6fcb629ebccc0f257de04bc8e7f4ef247c
Author: pkalinnikov <pkalinnikov@chromium.org>
Date: Fri Jan 13 18:30:38 2017

Match only prefixes of histogram names.

Fix the bug that HistogramTester::GetTotalCountsForPrefix returns histograms
which contain the query string as substrings, not as prefixes.

Additionally, omit explicit base:: namespace here and there, because the files
are already in this namespace.

BUG= 659977 

Review-Url: https://codereview.chromium.org/2628843002
Cr-Commit-Position: refs/heads/master@{#443620}

[modify] https://crrev.com/63e22b6fcb629ebccc0f257de04bc8e7f4ef247c/base/test/histogram_tester.cc
[modify] https://crrev.com/63e22b6fcb629ebccc0f257de04bc8e7f4ef247c/base/test/histogram_tester.h
[modify] https://crrev.com/63e22b6fcb629ebccc0f257de04bc8e7f4ef247c/base/test/histogram_tester_unittest.cc