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This CL is experimental, and aims to see if a changing surface id for
the root view could be at the heart of the flakey tests reference by
the associated bug.

One flakey test is re-enabled to provide some initial data.

The surface id idea is cherry-picked from kinuko@'s CL at
https://chromium-review.googlesource.com/c/chromium/src/+/1126598 .

Bug: 833380
Change-Id: I3cda4f5214a5bf19e711f95303a6b65b4ff2410c
Reviewed-on: https://chromium-review.googlesource.com/1172723
Commit-Queue: James MacLean <wjmaclean@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#583027}