GitLab

Implemented IAccessibleText::get_offsetAtPoint for
IA2_COORDTYPE_SCREEN_RELATIVE with associated unittests

get_offsetAtPoint invokes AXPlatformNodeDelegate::
GetInnerTextRangeBoundsRect to retrieve the bounds of each character of
its text. If the input (x, y) in screen coordinate is inside one of the character
bounds, we return the text offset of that character bounds.


Additionally, NVDA also requires this API to be implemented in order
for announcing text content on mouse over to work (crbug.com/1006277).

API doc:
https://accessibility.linuxfoundation.org/a11yspecs/ia2/docs/html/interface_i_accessible_text.html#a9e6bcc4589b93498ecf84d9c8b5326a0

Bug: 996407
Change-Id: I9c91734b2defde495e0f4b64cbcd34be3b5d44c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1832296Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Kurt Catti-Schmidt <kschmi@microsoft.com>
Commit-Queue: Victor Fei <vicfei@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#703841}