GitLab

This is a reland of a6f6697e

The test, GetAccessibleTabModalDialogTitle, failed on OSX because
tab-modal dialogs are treated as native windows in Voiceover.
This fix is unnecessary on OSX so the test is now disabled there.

Original change's description:
> Tab modal dialog title should be accessible window title
>
> Tab modal dialogs (ui::MODAL_TYPE_CHILD) should report their title
> to AT (insert+T on JAWS and NVDA) when active. To accomplish this,
> BrowserView::GetAccessibleWindowTitle should report the title of
> the dialog when one is active.
>
> Bug: 775680
> Test: browser_tests.exe --gtest_filter=BrowserViewTest.GetAccessibleTabModalDialogTitle
> Change-Id: Ie693e1627c87e4d97eede64381d80dab31635642
> Reviewed-on: https://chromium-review.googlesource.com/1184039
> Commit-Queue: James Wallace-Lee <jamwalla@chromium.org>
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#587371}

Bug: 775680, 879074, 879253
Change-Id: I4351a6487a4cb582383fe18b97e825a986464f59
Reviewed-on: https://chromium-review.googlesource.com/1197333Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: James Wallace-Lee <jamwalla@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587845}