Add RAF tests to blink_perf.canvas benchmark.

Current canvas benchmarks only measure CPU time.
Using requestAnimationFrame (raf) in javascript we can
measure CPU + raster + GPU time. This CL adds a mode to
blink_perf.py that runs canvas all canvas test in a way
that takes raster and GPU time into account.

Roughly doubles the duration of `blink_perf.canvas`
benchmark from ~2 minutes to ~4 minutes on a linux desktop.

Bug: 894043
Change-Id: I2fdd13af75615802266fa39a01db3e883f2c95bc
Reviewed-on: https://chromium-review.googlesource.com/c/1300038
Reviewed-by: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Commit-Queue: Aaron Krajeski <aaronhk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606849}
21 files changed