[Accessibility] Add histograms for Android reduce-motion API

This histogram will be used to guide the implementation of the CSS
prefers-reduced-motion media feature. The primary goal is to compare
usage levels across platforms.

Bug: 722548
Change-Id: I9162d4e9df2e04afa0c8716266c2f0dc2c57b2ac
Reviewed-on: https://chromium-review.googlesource.com/c/1330827
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Stephen McGruer <smcgruer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#608052}
6 files changed