Mash: remove //chrome dependencies from BrowserFrameHeaderAsh

This is a first step towards moving BrowserFrameHeaderAsh into
//ash/public and making it useable both in Ash (for Mash) and Chrome
(for classic).

Bug: 836992
Change-Id: I76109ef3949f803e87c153008c0bf462e8228492
Reviewed-on: https://chromium-review.googlesource.com/1042786
Commit-Queue: Evan Stade <estade@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555908}
11 files changed