GitLab

Remove the use of a do while loop in AccessibilityBridgeTests so tests
don't have the opportunity to run indefinitely.
Also remove special handling of the case where this is no root node as
this is now supported by the Semantics Manager.

Testing: CQ

Bug: 973095
Change-Id: I014506bf77fa11b7f33e115b601b9bfaa781b8e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1924714Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Commit-Queue: Sharon Yang <yangsharon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#717705}