commit 57d5843fce7227f9143f4e03a9931902a83cc2d1
author altimin <altimin@chromium.org> Sat May 13 02:49:18 2017 +0900
committer Qijiang Fan <fqj@google.com> Fri Jun 05 06:06:14 2020 +0900
tree 8212fd990768cdd93595de5592674883f7d34fd3
parent 5d1878fddb23e8edb8ef32693479db4e142b2706

[histogram] Make histograms more resistant to overflows.

Instead of calculating deltas from cumulative snapshots, store unlogged
histogram samples in a separate HistogramSample object.
This will reduce overflows from long-running sessions given that data
between UMA pings fits into 32-bit integer.

BUG=719446

Review-Url: https://codereview.chromium.org/2867303004
Cr-Commit-Position: refs/heads/master@{#471359}


CrOS-Libchrome-Original-Commit: 498c838a685f07dda12f74620f9a13ae0cf62383