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Add some trace-events to track the peak gpu memory usage, and the steps
when the peak usage changes.

Screenshot: https://i.imgur.com/VXtOodN.png

BUG=908462

Change-Id: Ic03d69f20ab4de06606f6ca5f4449b7993a8cb6a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1984899
Auto-Submit: Sadrul Chowdhury <sadrul@chromium.org>
Commit-Queue: Eric Karl <ericrk@chromium.org>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#728077}