Makes WorkspaceLayoutManager use ash/wm/common types

ash/wm/common/wm_root_window_controller.h

Index: ash/wm/common/wm_root_window_controller.h
diff --git a/ash/wm/common/wm_root_window_controller.h b/ash/wm/common/wm_root_window_controller.h
index 1c263b1d695c420c7f5923740b839565ecaedbe2..4d5e02327985752314ff4b296bec3ab1733bcadd 100644
--- a/ash/wm/common/wm_root_window_controller.h
+++ b/ash/wm/common/wm_root_window_controller.h
@@ -12,6 +12,9 @@
 #include "ui/views/widget/widget.h"
 
 namespace ash {
+
+class AlwaysOnTopController;
+
 namespace wm {
 
 class WmGlobals;
@@ -32,6 +35,8 @@ class ASH_EXPORT WmRootWindowController {
 
   virtual WorkspaceWindowState GetWorkspaceWindowState() = 0;
 
+  virtual AlwaysOnTopController* GetAlwaysOnTopController() = 0;
+
   virtual WmShelf* GetShelf() = 0;
 
   // Returns the window associated with this WmRootWindowController.