Add update available icon in system tray

chrome/browser/upgrade_detector.h

Index: chrome/browser/upgrade_detector.h
diff --git a/chrome/browser/upgrade_detector.h b/chrome/browser/upgrade_detector.h
index bc8542c8a9dd7335691449bdf129286fba556ca6..584fdc7a46638b0582dffbe554a72c55c49291fe 100644
--- a/chrome/browser/upgrade_detector.h
+++ b/chrome/browser/upgrade_detector.h
@@ -101,6 +101,11 @@ class UpgradeDetector {
   // Sends out UPGRADE_RECOMMENDED notification and set notify_upgrade_.
   void NotifyUpgradeRecommended();
 
+  // The function that sends out a notification that lets the rest of the UI
+  // know we should notify the user that a new update is available to download
+  // over cellular connection.
+  void NotifyUpdateOverCellularAvailable();
+
   // Triggers a critical update, which starts a timer that checks the machine
   // idle state. Protected and virtual so that it could be overridden by tests.
   virtual void TriggerCriticalUpdate();