Add an API to component_updater that asks to do an update check "now".

chrome/browser/component_updater/component_updater_service.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
 #define CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 121 matching lines @@
   virtual Status Start() = 0;
 
   // Stop doing update checks. In-flight requests and pending installations
   // will not be canceled.
   virtual Status Stop() = 0;
 
   // Add component to be checked for updates. You can call this method
   // before calling Start().
   virtual Status RegisterComponent(const CrxComponent& component) = 0;
 
+  // Ping for an update check for a previously registered component.
+  virtual Status PingUpdateCheck(const CrxComponent& component) = 0;

[jvoung (off chromium), 2013/01/25 17:48:30]

Would it make sense to add a callback parameter, or just have people register
against the NotificationService and listen for
NOTIFICATION_COMPONENT_UPDATE_READY.

If they listen for the notification... what if there is an error and the ping
does nothing?  Listen component updater going back to sleep, and use that as a
signal?

+
   virtual ~ComponentUpdateService() {}
 };
 
 // Creates the component updater. You must pass a valid |config| allocated on
 // the heap which the component updater will own.
 ComponentUpdateService* ComponentUpdateServiceFactory(
     ComponentUpdateService::Configurator* config);
 
 #endif  // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
-