Component updater on-demand logic with ResourceThrottle

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>
 
 #include "base/version.h"
 #include "url/gurl.h"
 
 namespace base {
 class DictionaryValue;
 class FilePath;
 }
 
 namespace net {
 class URLRequestContextGetter;
+class URLRequest;
+}
+
+namespace content {
+class ResourceThrottle;
 }
 
 class ComponentPatcher;
 
 // Component specific installers must derive from this class and implement
 // OnUpdateError() and Install(). A valid instance of this class must be
 // given to ComponentUpdateService::RegisterComponent().
 class ComponentInstaller {
  public :
   // Called by the component updater on the UI thread when there was a
@@ skipping 154 matching lines @@
   // There is no guarantee that the item will actually be updated,
   // since another item may be chosen to be updated. Since there is
   // no time guarantee, there is no notification if the item is not updated.
   // However, the ComponentInstaller should know if an update succeeded
   // via the Install() hook.
   virtual Status CheckForUpdateSoon(const std::string& component_id) = 0;
 
   // Returns a list of registered components.
   virtual void GetComponents(std::vector<CrxComponentInfo>* components) = 0;
 
+  // Returns a resource throttler. It imeans that a component will be downloaded
+  // and installed before the resource is untrottled. Note that is this called
+  // from the IO thread.
+  virtual content::ResourceThrottle* GetResourceThrottle(
+      net::URLRequest* request, const char* crx_id) = 0;
+
   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_