Use mojo SystemTray interfaces for both mash and classic ash

chrome/browser/ui/ash/chrome_shell_delegate.cc

Index: chrome/browser/ui/ash/chrome_shell_delegate.cc
diff --git a/chrome/browser/ui/ash/chrome_shell_delegate.cc b/chrome/browser/ui/ash/chrome_shell_delegate.cc
index c4e185a244bc1206ca0046cf6fc29cb01cadf0c3..141aa1a0266fa83a6ba9048c0cf82697f747bc82 100644
--- a/chrome/browser/ui/ash/chrome_shell_delegate.cc
+++ b/chrome/browser/ui/ash/chrome_shell_delegate.cc
@@ -73,6 +73,7 @@
 #include "components/user_manager/user_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/user_metrics.h"
+#include "content/public/common/mojo_shell_connection.h"
 #include "ui/app_list/presenter/app_list_presenter.h"
 #include "ui/aura/window.h"
 #include "ui/base/ime/chromeos/input_method_manager.h"
@@ -324,6 +325,10 @@ ChromeShellDelegate::ChromeShellDelegate()
 ChromeShellDelegate::~ChromeShellDelegate() {
 }
 
+shell::Connector* ChromeShellDelegate::GetShellConnector() const {
+  return content::MojoShellConnection::GetForProcess()->GetConnector();
+}
+
 bool ChromeShellDelegate::IsFirstRunAfterBoot() const {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       chromeos::switches::kFirstExecAfterBoot);