Folds WmRootWindowController into RootWindowController

Folds WmRootWindowController into RootWindowController

This is (mostly) the bare minimum to merge the two. Future patches
will cleanup WmWindow usage.

BUG=671246
TEST=none
R=jamescook@chromium.org

[sky, 2017-01-10 22:45:22]

Sorry for the ginormo review. The code in RootWindowController is nearly an
exact copy of what was in WmRootWindowController. It's not exact, which makes
for a painful review. If you prefer, I could change this patch so that I keep
wm_root_window_controller.cc, but everything is still in RootWindowController.
This would make it easier to see what actually changed.

https://codereview.chromium.org/2625843002/diff/1/ash/root_window_controller.cc
File ash/root_window_controller.cc (right):

https://codereview.chromium.org/2625843002/diff/1/ash/root_window_controller....
ash/root_window_controller.cc:632: // ShelfWidget* shelf_widget =
GetShelf()->shelf_widget();
One question here. The commented code is what mash had where as ash had the
CHECK. Do I keep the CHECK and remove the (commented out) conditionals?

[James Cook, 2017-01-11 00:49:55]

Starting to look...

https://codereview.chromium.org/2625843002/diff/1/ash/root_window_controller.cc
File ash/root_window_controller.cc (right):

https://codereview.chromium.org/2625843002/diff/1/ash/root_window_controller....
ash/root_window_controller.cc:632: // ShelfWidget* shelf_widget =
GetShelf()->shelf_widget();
On 2017/01/10 22:45:22, sky wrote:
> One question here. The commented code is what mash had where as ash had the
> CHECK. Do I keep the CHECK and remove the (commented out) conditionals?

I would keep the CHECK. Feel free to ping me if you get test failures.

[sky, 2017-01-11 05:54:38]

On 2017/01/11 00:49:55, James Cook wrote:
> Starting to look...
> 
>
https://codereview.chromium.org/2625843002/diff/1/ash/root_window_controller.cc
> File ash/root_window_controller.cc (right):
> 
>
https://codereview.chromium.org/2625843002/diff/1/ash/root_window_controller....
> ash/root_window_controller.cc:632: // ShelfWidget* shelf_widget =
> GetShelf()->shelf_widget();
> On 2017/01/10 22:45:22, sky wrote:
> > One question here. The commented code is what mash had where as ash had the
> > CHECK. Do I keep the CHECK and remove the (commented out) conditionals?
> 
> I would keep the CHECK. Feel free to ping me if you get test failures.

git cl got confused with the removal of wm_root_window_controller and then
adding it back. So, I closed this and created a new patch:
https://codereview.chromium.org/2620153003/ .