Use mojo SystemTray interfaces for both mash and classic ash

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 0a09d084b1a5a2e6a8ebff1d85b1b30003dbf6cc..adc9792126a5f809aeedc2035f5518d94b52f817 100644
--- a/ash/common/wm_shell.h
+++ b/ash/common/wm_shell.h
@@ -34,6 +34,10 @@ class Insets;
 class Point;
 }
 
+namespace shell {
+class Connector;
+}
+
 namespace views {
 class PointerWatcher;
 enum class PointerWatcherEventTypes;
@@ -62,6 +66,7 @@ class ShelfWindowWatcher;
 class ShellDelegate;
 class ShellObserver;
 class SystemTrayDelegate;
+class SystemTrayController;
 class SystemTrayNotifier;
 class ToastManager;
 class WallpaperController;
@@ -96,7 +101,8 @@ class ASH_EXPORT WmShell {
   static WmShell* Get();
   static bool HasInstance() { return instance_ != nullptr; }
 
-  void Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool);
+  void Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool,
+                  ::shell::Connector* connector);
   virtual void Shutdown();
 
   ShellDelegate* delegate() { return delegate_.get(); }
@@ -144,6 +150,10 @@ class ASH_EXPORT WmShell {
 
   ShelfModel* shelf_model() { return shelf_model_.get(); }
 
+  SystemTrayController* system_tray_controller() {
+    return system_tray_controller_.get();
+  }
+
   SystemTrayNotifier* system_tray_notifier() {
     return system_tray_notifier_.get();
   }
@@ -453,6 +463,7 @@ class ASH_EXPORT WmShell {
   std::unique_ptr<ShelfDelegate> shelf_delegate_;
   std::unique_ptr<ShelfModel> shelf_model_;
   std::unique_ptr<ShelfWindowWatcher> shelf_window_watcher_;
+  std::unique_ptr<SystemTrayController> system_tray_controller_;
   std::unique_ptr<SystemTrayNotifier> system_tray_notifier_;
   std::unique_ptr<SystemTrayDelegate> system_tray_delegate_;
   std::unique_ptr<ToastManager> toast_manager_;