Add update available icon in system tray

ash/system/tray/system_tray_controller.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/system/tray/system_tray_controller.h"
 
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
 #include "ash/shell_port.h"
 #include "ash/system/tray/system_tray.h"
@@ skipping 52 matching lines @@
 void SystemTrayController::ShowChromeSlow() {
   if (system_tray_client_)
     system_tray_client_->ShowChromeSlow();
 }
 
 void SystemTrayController::ShowIMESettings() {
   if (system_tray_client_)
     system_tray_client_->ShowIMESettings();
 }
 
+void SystemTrayController::ShowAboutChromeOS(bool check_for_update) {
+  if (system_tray_client_)
+    system_tray_client_->ShowAboutChromeOS(check_for_update);
+}
+
 void SystemTrayController::ShowHelp() {
   if (system_tray_client_)
     system_tray_client_->ShowHelp();
 }
 
 void SystemTrayController::ShowAccessibilityHelp() {
   if (system_tray_client_)
     system_tray_client_->ShowAccessibilityHelp();
 }
 
@@ skipping 120 matching lines @@
   for (WmWindow* root : ShellPort::Get()->GetAllRootWindows()) {
     ash::SystemTray* tray = root->GetRootWindowController()->GetSystemTray();
     // External monitors might not have a tray yet.
     if (!tray)
       continue;
     tray->tray_update()->ShowUpdateIcon(severity, factory_reset_required,
                                         update_type);
   }
 }
 
+void SystemTrayController::ShowUpdateOverCellularAvailableIcon() {
+  // Show the icon on all displays.
+  for (WmWindow* root : ShellPort::Get()->GetAllRootWindows()) {
+    ash::SystemTray* tray = root->GetRootWindowController()->GetSystemTray();
+    // External monitors might not have a tray yet.
+    if (!tray)
+      continue;
+    tray->tray_update()->ShowUpdateOverCellularAvailableIcon();
+  }
+}
+
 }  // namespace ash