GitLab

Adds browser proxies for the A11y Page, Manage A11y Subpage, and Text
to Speech subpage. Allows the future creation of test browser proxies
to create tests for deep linking in the A11y pages.

Bug: 1084154
Change-Id: I83e4b69fac1b07b8e2a2c9813ac57be1642a0e99
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2399570
Commit-Queue: Daniel Classon <dclasson@google.com>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805566}