Revert of Rate limit programmatic update checks for extensions

chrome/browser/extensions/api/runtime/chrome_runtime_api_delegate.h

 // Copyright 2014 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_EXTENSIONS_API_RUNTIME_CHROME_RUNTIME_API_DELEGATE_H_
 #define CHROME_BROWSER_EXTENSIONS_API_RUNTIME_CHROME_RUNTIME_API_DELEGATE_H_
 
 #include <map>
-#include <string>
-#include <utility>
+#include <vector>
 
 #include "base/macros.h"
-#include "base/scoped_observer.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/api/runtime/runtime_api.h"
 #include "extensions/browser/api/runtime/runtime_api_delegate.h"
-#include "extensions/browser/extension_registry_observer.h"
 
 namespace base {
-class TickClock;
 class TimeTicks;
 }
 
 namespace content {
 class BrowserContext;
 class NotificationDetails;
 class NotificationSource;
 }
 
 namespace extensions {
-class ExtensionRegistry;
 class RuntimeAPI;
 class UpdateObserver;
 }
 
 class ChromeRuntimeAPIDelegate : public extensions::RuntimeAPIDelegate,
-                                 public content::NotificationObserver,
-                                 public extensions::ExtensionRegistryObserver {
+                                 public content::NotificationObserver {
  public:
   explicit ChromeRuntimeAPIDelegate(content::BrowserContext* context);
   ~ChromeRuntimeAPIDelegate() override;
 
-  // Sets a custom TickClock to use in tests.
-  static void set_tick_clock_for_tests(base::TickClock* clock);
-
  private:
   friend class extensions::RuntimeAPI;
 
   // extensions::RuntimeAPIDelegate implementation.
   void AddUpdateObserver(extensions::UpdateObserver* observer) override;
   void RemoveUpdateObserver(extensions::UpdateObserver* observer) override;
   base::Version GetPreviousExtensionVersion(
       const extensions::Extension* extension) override;
   void ReloadExtension(const std::string& extension_id) override;
   bool CheckForUpdates(const std::string& extension_id,
                        const UpdateCheckCallback& callback) override;
   void OpenURL(const GURL& uninstall_url) override;
   bool GetPlatformInfo(extensions::api::runtime::PlatformInfo* info) override;
   bool RestartDevice(std::string* error_message) override;
   bool OpenOptionsPage(const extensions::Extension* extension) override;
 
   // content::NotificationObserver implementation.
   void Observe(int type,
                const content::NotificationSource& source,
                const content::NotificationDetails& details) override;
 
-  // ExtensionRegistryObserver implementation.
-  void OnExtensionInstalled(content::BrowserContext* browser_context,
-                            const extensions::Extension* extension,
-                            bool is_update) override;
-
   void UpdateCheckComplete(const std::string& extension_id);
   void CallUpdateCallbacks(const std::string& extension_id,
                            const UpdateCheckResult& result);
 
   content::BrowserContext* browser_context_;
 
   content::NotificationRegistrar registrar_;
 
   // Whether the API registered with the ExtensionService to receive
   // update notifications.
   bool registered_for_updates_;
 
   // Map to prevent extensions from getting stuck in reload loops. Maps
   // extension id to the last time it was reloaded and the number of times
   // it was reloaded with not enough time in between reloads.
   std::map<std::string, std::pair<base::TimeTicks, int> > last_reload_time_;
 
-  // Information about update checks, keyed by extension id.
-  struct UpdateCheckInfo;
-  std::map<std::string, UpdateCheckInfo> update_check_info_;
+  // Pending update checks.
+  typedef std::vector<UpdateCheckCallback> UpdateCallbackList;
+  typedef std::map<std::string, UpdateCallbackList> UpdateCallbackMap;
+  UpdateCallbackMap pending_update_checks_;
 
-  ScopedObserver<extensions::ExtensionRegistry,
-                 extensions::ExtensionRegistryObserver>
-      extension_registry_observer_;
-
+ private:
   DISALLOW_COPY_AND_ASSIGN(ChromeRuntimeAPIDelegate);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_RUNTIME_CHROME_RUNTIME_API_DELEGATE_H_