The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0

commit deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0
Author: manzagop <manzagop@chromium.org>
Date: Wed Mar 08 17:00:01 2017

Bound the impact of system instability on chrome instability.

Add to stability reports whether the containing system session was clean. This information is derived in the following way:
- add a timestamp to the stability file when chrome starts
- when processing unclean chrome shutdowns, inspect the system event logs for the past X sessions and interpret the stability file timestamps in that context

The log inspection and analysis is in system_session_analyzer_win*, the rest is plumbing.

BUG=695987

Review-Url: https://codereview.chromium.org/2715903003
Cr-Commit-Position: refs/heads/master@{#455476}

[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/chrome/browser/chrome_browser_field_trials_desktop.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/BUILD.gn
[add] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/fetch_system_session_events_main_win.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/postmortem_report_collector.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/postmortem_report_collector.h
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/postmortem_report_collector_unittest.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/stability_data_names.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/stability_data_names.h
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/stability_report.proto
[add] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/system_session_analyzer_win.cc
[add] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/system_session_analyzer_win.h
[add] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/system_session_analyzer_win_unittest.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/components/browser_watcher/watcher_metrics_provider_win.cc
[modify] https://crrev.com/deb62bfb3b4c7c2b78d6b6205766d9cf10ca39a0/tools/metrics/histograms/histograms.xml