Add an update warning for downloading over mobile data

chromeos/dbus/update_engine_client.h

Index: chromeos/dbus/update_engine_client.h
diff --git a/chromeos/dbus/update_engine_client.h b/chromeos/dbus/update_engine_client.h
index 94c89ea7b50546c2f449b43f537636602f90d047..a52143376c8de2621fb712a60d55e335f49dbb5e 100644
--- a/chromeos/dbus/update_engine_client.h
+++ b/chromeos/dbus/update_engine_client.h
@@ -40,7 +40,8 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
     UPDATE_STATUS_FINALIZING,
     UPDATE_STATUS_UPDATED_NEED_REBOOT,
     UPDATE_STATUS_REPORTING_ERROR_EVENT,
-    UPDATE_STATUS_ATTEMPTING_ROLLBACK
+    UPDATE_STATUS_ATTEMPTING_ROLLBACK,
+    UPDATE_STATUS_NEED_PERMISSION_TO_UPDATE
   };
 
   // The status of the ongoing update attempt.
@@ -149,6 +150,18 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
       bool allowed,
       const base::Closure& callback) = 0;
 
+  // Called once SetUpdateOverCellularTarget() is complete. Takes one parameter;
+  // - success: indicates whether the target is set successfully.
+  typedef base::Callback<void(bool)> SetTargetCallback;
+
+  // Set the target in the preferences maintained by update engine which then
+  // performs update to this given target after |RequestUpdateCheck| is invoked
+  // in the |callback|.
+  virtual void SetUpdateOverCellularTarget(
+      const std::string& target_version,
+      int64_t target_size,
+      const SetTargetCallback& callback) = 0;
+
   // Returns an empty UpdateCheckCallback that does nothing.
   static UpdateCheckCallback EmptyUpdateCheckCallback();