GitLab

This adds an implementation of ITextRangeProvider::MoveEndpointByUnit
for TextUnit_Page and TextUnit_Document.

Behavior for TextUnit_Page is identical to TextUnit_Document, as web
pages are not paginated.

TextUnit_Document behavior is to always move to the beginning or end of
the top-level document. iframes will jump out of the current iframe and
to the end of the top-most document. There currently is buggy behavior
for the iframe case, and a follow up task will address this issue.

Bug: 928948
Change-Id: I87056282dbe037e95a3cd43b29e10a849a9a9a0e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1554132
Commit-Queue: Alison Maher <almaher@microsoft.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#649157}