[Telemetry] Add option to save a CPU profile for a benchmark.

This patch only adds the linux perf profiler. I'm planning to add mac and
android profilers in follow up patches.

This was inspired by profilers in blink's run-perf-tests.

BUG=None
TEST=tools/perf/run_multipage_benchmarks --browser=system page_cycler tools/perf/page_sets/page_cycler/moz.json --page-filter=bugzilla --profiler-tool=perf --profiler-dir=/tmp/foo
NOTRY=True

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=199239

Review URL: https://chromiumcodereview.appspot.com/14866005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@199242 0039d316-1c4b-4281-b951-d872f2087c98
14 files changed