Will require a chromium-side patch to enable boolean histograms.

BUG=angleproject:966
BUG=436191

Change-Id: I3026c73894fbbff521503b377955816a8e831df8
Reviewed-on: https://chromium-review.googlesource.com/271174Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>