GitLab

This CL factors CPU profiling code out of chrome/ and into content/ to support
CPU profiling Headless Chromium.  headless_content_main_delegate.cc has been
modified to honor CPU profiling flags à la chrome_main_delegate.cc.

Bug: 890456
Change-Id: I76842c5936de82d6bd42354c461aff9e0d273248
Reviewed-on: https://chromium-review.googlesource.com/c/1312157
Commit-Queue: Bryce Thomas <bryct@amazon.com>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#605942}