ash: Add SessionController/Client mojo interfaces

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 1dff4ae3131b6042aa392e9ed7087d56236e5568..4eba9189b8e92b05830d289d6e6281db50bece4f 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -56,6 +56,7 @@ class MaximizeModeController;
 class MruWindowTracker;
 class PaletteDelegate;
 class ScopedDisableInternalMouseAndKeyboard;
+class SessionController;
 class SessionStateDelegate;
 class ShelfController;
 class ShelfDelegate;
@@ -156,6 +157,8 @@ class ASH_EXPORT WmShell {
 
   PaletteDelegate* palette_delegate() { return palette_delegate_.get(); }
 
+  SessionController* session_controller() { return session_controller_.get(); }
+
   ShelfController* shelf_controller() { return shelf_controller_.get(); }
 
   ShelfDelegate* shelf_delegate() { return shelf_delegate_.get(); }
@@ -494,6 +497,7 @@ class ASH_EXPORT WmShell {
   std::unique_ptr<MruWindowTracker> mru_window_tracker_;
   std::unique_ptr<mojom::NewWindowClient> new_window_client_;
   std::unique_ptr<PaletteDelegate> palette_delegate_;
+  std::unique_ptr<SessionController> session_controller_;
   std::unique_ptr<ShelfController> shelf_controller_;
   std::unique_ptr<ShelfDelegate> shelf_delegate_;
   std::unique_ptr<ShelfWindowWatcher> shelf_window_watcher_;