Mustash: Move RenderWidgetHostViewMus from frame_host => renderer_host

Mustash: Move RenderWidgetHostViewMus from frame_host => renderer_host

We are not yet addressing the subframe case so renderer_host is a better
place for this file.

BUG=551250
Committed: https://crrev.com/402274e42cb72fde4f48a4bb01664d0ad4533c69
Cr-Commit-Position: refs/heads/master@{#361057}

[Fady Samuel, 2015-11-22 22:12:17]

fsamuel@chromium.org changed reviewers:
+ ben@chromium.org, sadrul@chromium.org

[Fady Samuel, 2015-11-22 22:12:17]

+ben@ who suggested the change
+sadrul@ for OWNER approval.

[Ben Goodger (Google), 2015-11-22 22:21:49]

lgtm

[sadrul, 2015-11-22 22:42:14]

Note that code in renderer_host can't use code in frame_host, which has made
some changes in render_widget_host_view_aura tricky. I am not sure if that will
affect _mus much, but something to keep on mind.

With that, lgtm

[Fady Samuel, 2015-11-22 22:57:21]

On 2015/11/22 22:42:14, sadrul wrote:
> Note that code in renderer_host can't use code in frame_host, which has made
> some changes in render_widget_host_view_aura tricky. I am not sure if that
will
> affect _mus much, but something to keep on mind.
> 
> With that, lgtm

I plan to send out a design doc tomorrow afternoon (really a one pager, maybe
two) with a proposal for some changes we might need to make in content to
accommodate mustash. I'll think about how this might complicate things until
then. Thanks!

[Fady Samuel, 2015-11-22 22:57:34]

The CQ bit was checked by fsamuel@chromium.org

[commit-bot: I haz the power, 2015-11-22 22:57:40]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1467083002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1467083002/1

[commit-bot: I haz the power, 2015-11-22 23:38:13]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-22 23:38:44]

Patchset 1 (id:??) landed as
https://crrev.com/402274e42cb72fde4f48a4bb01664d0ad4533c69
Cr-Commit-Position: refs/heads/master@{#361057}