Removes WmRootWindowController subclasses

ash/mus/bridge/wm_window_mus.cc

Index: ash/mus/bridge/wm_window_mus.cc
diff --git a/ash/mus/bridge/wm_window_mus.cc b/ash/mus/bridge/wm_window_mus.cc
index 3e58848f506514e2ea42caf7d2a91dbf2062a3a8..324c31ebcf6d83ca208817274ed18bfbcb6f24c0 100644
--- a/ash/mus/bridge/wm_window_mus.cc
+++ b/ash/mus/bridge/wm_window_mus.cc
@@ -13,9 +13,9 @@
 #include "ash/common/wm_transient_window_observer.h"
 #include "ash/common/wm_window_observer.h"
 #include "ash/common/wm_window_property.h"
-#include "ash/mus/bridge/wm_root_window_controller_mus.h"
 #include "ash/mus/bridge/wm_shell_mus.h"
 #include "ash/mus/property_util.h"
+#include "ash/mus/root_window_controller.h"
 #include "ash/mus/window_manager.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/wm/window_properties.h"
@@ -57,17 +57,14 @@ WmWindowMus* WmWindowMus::Get(views::Widget* widget) {
   return WmWindowMus::Get(widget->GetNativeView());
 }
 
-const WmRootWindowControllerMus* WmWindowMus::GetRootWindowControllerMus()
-    const {
-  return WmRootWindowControllerMus::Get(aura_window()->GetRootWindow());
-}
-
 bool WmWindowMus::IsContainer() const {
   return GetShellWindowId() != kShellWindowId_Invalid;
 }
 
 WmRootWindowController* WmWindowMus::GetRootWindowController() {

[James Cook, 2017/01/10 22:41:13]

Could this override be eliminated in favor of WmWindowAura's version? If not,
should this be using aura_window()->GetRootWindow()?

[sky, 2017/01/10 23:06:56]

Good call. WmWindowAura's implementation works as long as change assertions in
RootWindowController::ForWindow.

-  return GetRootWindowControllerMus();
+  return RootWindowController::ForWindow(aura_window())
+      ->ash_root_window_controller()
+      ->wm_root_window_controller();
 }
 
 WmShell* WmWindowMus::GetShell() const {