GitLab

As part of the overall effort to share more code between the
accessibility component extensions, move Switch Access' RectUtil class
into the common/ directory.

This change is a pure refactor.

AX-Relnotes: n/a.
Bug: None.
Change-Id: I2980080ad643bef76720095c67bbd9165e645f6b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2368481Reviewed-by: Akihiro Ota <akihiroota@chromium.org>
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Cr-Commit-Position: refs/heads/master@{#801604}