Add concurrency check to HistogramSnapshotManager.
Using ThreadChecker causes problems when outside code is doing its
own synchronization between multiple calling threads so remove that
and add an atomic to do a run-time concurrency CHECK. This will
likely be removed in the future once it's well assured that concurrent
access is not the cause of the corrupted data structures.
Also, make known_histograms_ member "const" as it should have been from
the beginning.
BUG=719448, 600717
Review-Url: https://codereview.chromium.org/2871663003
Cr-Commit-Position: refs/heads/master@{#470178}
CrOS-Libchrome-Original-Commit: 947514553066c623a85712d05c3a01bd1bcbbffc
2 files changed