GitLab

Changes the internal configuration representation within
ThreadProfilerConfiguration to cleanly separate the configuration
representation for the browser process from the one for child
processes. The configuration state for the two does not overlap
conceptually so it's not desirable for them to share the same
representation.

Also explicitly separates the browser process configuration state
that governs whether to register a synthetic field trial from the
state that says what group to use when registering.

Bug: 1129939
Change-Id: I5d70be116e165e78c700db726f66f92230de514f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2438479
Commit-Queue: Mike Wittman <wittman@chromium.org>
Reviewed-by: Etienne Pierre-Doray <etiennep@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822872}