Use mojo SystemTray interfaces for both mash and classic ash

ash/common/wm_shell.cc

Index: ash/common/wm_shell.cc
diff --git a/ash/common/wm_shell.cc b/ash/common/wm_shell.cc
index ff23fb22180d11e66848a40277edb767f96be958..896814630763089efc8180427228d0d68b2c828d 100644
--- a/ash/common/wm_shell.cc
+++ b/ash/common/wm_shell.cc
@@ -23,6 +23,7 @@
 #include "ash/common/system/brightness_control_delegate.h"
 #include "ash/common/system/keyboard_brightness_control_delegate.h"
 #include "ash/common/system/toast/toast_manager.h"
+#include "ash/common/system/tray/system_tray_controller.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wallpaper/wallpaper_controller.h"
@@ -64,7 +65,8 @@ WmShell* WmShell::Get() {
   return instance_;
 }
 
-void WmShell::Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool) {
+void WmShell::Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool,
+                         shell::Connector* connector) {
   blocking_pool_ = pool;
 
   // Some delegates access WmShell during their construction. Create them here
@@ -84,6 +86,7 @@ void WmShell::Initialize(const scoped_refptr<base::SequencedWorkerPool>& pool) {
   new_window_delegate_.reset(delegate_->CreateNewWindowDelegate());
 
   wallpaper_controller_.reset(new WallpaperController(blocking_pool_));
+  system_tray_controller_.reset(new SystemTrayController(connector));
 }
 
 void WmShell::Shutdown() {