Componentize component_updater: Split content::ResourceThrottle from CUS.

chrome/browser/component_updater/component_updater_service.h

 // Copyright 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/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/version.h"
 #include "url/gurl.h"
 
 class ComponentsUI;
 
 namespace base {
 class DictionaryValue;
 class FilePath;
@@ skipping 143 matching lines @@
   // before calling Start().
   virtual Status RegisterComponent(const CrxComponent& component) = 0;
 
   // Returns a list of registered components.
   virtual std::vector<std::string> GetComponentIDs() const = 0;
 
   // Returns an interface for on-demand updates. On-demand updates are
   // proactively triggered outside the normal component update service schedule.
   virtual OnDemandUpdater& GetOnDemandUpdater() = 0;
 
+  // |callback| is called on the main thread once the component with |crx_id|
+  // is downloaded and installed. |callback| may be called synchronously

[Sorin Jianu, 2014/08/01 00:03:06]

We need to better document the intention and the functionality of the
|callback|.

[tommycli, 2014/08/05 21:30:25]

I rewrote parts of the comment. It's a bit long now, Let me know what changes to
make...

After writing the comment, I feel like we should rename this method.

+  // if component is already installed. The function implements a cooldown
+  // interval of 30 minutes. That means it will ineffective to call the
+  // function before the cooldown interval has passed. This behavior is intended
+  // to be defensive against programming bugs, usually triggered by web fetches,
+  // where the on-demand functionality is invoked too often.
+  virtual void MaybeThrottle(const std::string& crx_id,
+                             const base::Closure& callback) = 0;
+
   // Returns a task runner suitable for use by component installers.
   virtual scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner() = 0;
 
   virtual ~ComponentUpdateService() {}
 
  private:
   // Returns details about registered component in the |item| parameter. The
   // function returns true in case of success and false in case of errors.
   virtual bool GetComponentDetails(const std::string& component_id,
                                    CrxUpdateItem* item) const = 0;
 
   friend class ::ComponentsUI;
-  FRIEND_TEST_ALL_PREFIXES(ComponentUpdaterTest, ResourceThrottleLiveNoUpdate);
 };
 
 typedef ComponentUpdateService::Observer ServiceObserver;
 
 class OnDemandUpdater {
  public:
   virtual ~OnDemandUpdater() {}
 
-  // Returns a network resource throttle. It means that a component will be
-  // downloaded and installed before the resource is unthrottled. This function
-  // can be called from the IO thread. The function implements a cooldown
-  // interval of 30 minutes. That means it will ineffective to call the
-  // function before the cooldown interval has passed. This behavior is intended
-  // to be defensive against programming bugs, usually triggered by web fetches,
-  // where the on-demand functionality is invoked too often.
-  virtual content::ResourceThrottle* GetOnDemandResourceThrottle(
-      net::URLRequest* request,
-      const std::string& crx_id) = 0;
-
  private:
   friend class OnDemandTester;
   friend class ::ComponentsUI;
 
   // Triggers an update check for a component. |component_id| is a value
   // returned by GetCrxComponentID(). If an update for this component is already
   // in progress, the function returns |kInProgress|. If an update is available,
   // the update will be applied. The caller can subscribe to component update
   // service notifications to get an indication about the outcome of the
   // on-demand update. The function does not implement any cooldown interval.
   virtual ComponentUpdateService::Status OnDemandUpdate(
       const std::string& component_id) = 0;
 };
 
 // Creates the component updater. You must pass a valid |config| allocated on
 // the heap which the component updater will own.
 ComponentUpdateService* ComponentUpdateServiceFactory(Configurator* config);
 
 }  // namespace component_updater
 
 #endif  // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_