Moves ToastManager from Shell to WmShell

ash/common/wm_shell.h

Index: ash/common/wm_shell.h
diff --git a/ash/common/wm_shell.h b/ash/common/wm_shell.h
index 9b82c36a60b11eb400ec244ee4b307fc24044209..ced98b5e340c87c7d87646fe4e0ce38cf7734596 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -35,6 +35,7 @@ class ShellDelegate;
 class ShellObserver;
 class SystemTrayDelegate;
 class SystemTrayNotifier;
+class ToastManager;
 class WindowCycleController;
 class WindowCycleEventFilter;
 class WindowResizer;
@@ -100,6 +101,8 @@ class ASH_EXPORT WmShell {
     return system_tray_delegate_.get();
   }
 
+  ToastManager* toast_manager() { return toast_manager_.get(); }
+
   WindowCycleController* window_cycle_controller() {
     return window_cycle_controller_.get();
   }
@@ -259,6 +262,8 @@ class ASH_EXPORT WmShell {
   void CreateMruWindowTracker();
   void DeleteMruWindowTracker();
 
+  void DeleteToastManager();
+
  private:
   friend class AcceleratorControllerTest;
   friend class Shell;
@@ -279,6 +284,7 @@ class ASH_EXPORT WmShell {
   std::unique_ptr<MruWindowTracker> mru_window_tracker_;
   std::unique_ptr<SystemTrayNotifier> system_tray_notifier_;
   std::unique_ptr<SystemTrayDelegate> system_tray_delegate_;
+  std::unique_ptr<ToastManager> toast_manager_;
   std::unique_ptr<WindowCycleController> window_cycle_controller_;
   std::unique_ptr<WindowSelectorController> window_selector_controller_;