Instrument child process field trial creation to measure success.

This will let us see how many clients are falling back to using
the command-line to synchronize state and also whether any of
them are failing to create field trials from shared memory or
command line.

Bug: 867558
Change-Id: If1dd1f694686a98b67a553344f3a3e2289424430
Commit-Queue: Alexei Svitkine <>
Reviewed-by: Brian White <>
Cr-Commit-Position: refs/heads/master@{#578036}
2 files changed