Implement "open link as user" context menu entry
The menu entry is only present if multiple profiles are defined, and
only displays those that currently have open windows.
If only a single other profile has an open window, no sub-menu is
created
BUG=
103073
R=pkasting@chromium.org
TEST=ContextMenuBrowserTest.OpenLinkInProfile*
Committed:
https://crrev.com/3917ff9e77c4da3d2d56398cebdc52312b2b63d3
Cr-Commit-Position: refs/heads/master@{#356023}