BrowserView should not report that guest mode is incognito.

The existing comment in the code noted this is probably incorrect and suggested
auditing the callers.  In looking at the callers, it looks like they all care
about this for the purpos of "what color/resource ID should be used for the
window".  Since guest windows should appear like normal windows and not OTR
windows (AFAIK), I believe the callers all want this change.

Bug: none
Change-Id: I51b2d776d71a0cec296de04a8304762a32ba4b7e
Reviewed-on: https://chromium-review.googlesource.com/c/1396957
Reviewed-by: Bret Sepulveda <bsep@chromium.org>
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Cr-Commit-Position: refs/heads/master@{#620501}
1 file changed