tree 8cc3f7d9151adafce37211846804a8134c836d57
parent 0715a9e3545106c456d91fc48f18119743639957
author georgesak <georgesak@chromium.org> 1439567557 +0900
committer Qijiang Fan <fqj@google.com> 1591266459 +0900

[ETW Export] Add polling for ETW keyword.

This adds a background low-priority thread for each process that monitors the keyword and adjusts the categories accordingly. This allows users to start profiling (using UIForETW or Xpef directly) and specify which categories to enable, without having to restart Chrome.

Notes:
- TraceEventETWExport is a friend of TraceLog (see comment in code).
- ETW exporting still needs to be enabled using the command line or in about:flags.

BUG=491909

Review URL: https://codereview.chromium.org/1279353002

Cr-Commit-Position: refs/heads/master@{#343393}


CrOS-Libchrome-Original-Commit: 3bd527974c0cea7b1e0e9965fa9e13823861ebb6