GitLab

When to change source during a tab sharing session, the new picker will
only be available on the tab which starts the session. If that tab is
not on the front, user may probably miss the picker.

This cl is to bring the tab up to front before showing the picker for
easy notice. If use selects to cancel the source changing, this cl will
activate the previous shared tab to continue the sharing session.

Bug: 892201
Change-Id: I51c6436095df37f3afb3d28aebbfb9e4bb03f3a5
Reviewed-on: https://chromium-review.googlesource.com/c/1423700Reviewed-by: Emircan Uysaler <emircan@chromium.org>
Commit-Queue: Weiyong Yao <braveyao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#625800}