[Extensions] Short-circuit activity logging if not enabled

chrome/browser/extensions/activity_log/activity_log.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_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_H_
 #define CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/observer_list_threadsafe.h"
 #include "base/scoped_observer.h"
-#include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "chrome/browser/extensions/activity_log/activity_actions.h"
 #include "chrome/browser/extensions/activity_log/activity_log_policy.h"
-#include "extensions/browser/api_activity_monitor.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "extensions/browser/script_execution_observer.h"
 #include "extensions/common/dom_action_types.h"
 
 class Profile;
 
 namespace content {
 class BrowserContext;
 }
 
 namespace user_prefs {
 class PrefRegistrySyncable;
 }
 
 namespace extensions {
 class Extension;
 class ExtensionRegistry;
 
 // A utility for tracing interesting activity for each extension.
 // It writes to an ActivityDatabase on a separate thread to record the activity.
 // Each profile has different extensions, so we keep a different database for
 // each profile.
 //
 class ActivityLog : public BrowserContextKeyedAPI,
-                    public ApiActivityMonitor,
                     public ScriptExecutionObserver,
-                    public ExtensionRegistryObserver {
+                    public ExtensionRegistryObserver,
+                    public content::NotificationObserver {
  public:
   // Observers can listen for activity events. There is probably only one
   // observer: the activityLogPrivate API.
   class Observer {
    public:
     virtual void OnExtensionActivity(scoped_refptr<Action> activity) = 0;
   };
 
   static BrowserContextKeyedAPIFactory<ActivityLog>* GetFactoryInstance();
 
   // ActivityLog is a KeyedService, so don't instantiate it with
   // the constructor; use GetInstance instead.
   static ActivityLog* GetInstance(content::BrowserContext* context);
 
   // Add/remove observer: the activityLogPrivate API only listens when the
   // ActivityLog extension is registered for an event.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
   // Logs an extension action: passes it to any installed policy to be logged
   // to the database, to any observers, and logs to the console if in testing
   // mode.
   void LogAction(scoped_refptr<Action> action);
 
+  // Returns true if an event for the given extension should be logged.
+  bool ShouldLog(const std::string& extension_id) const;
+
   // Gets all actions that match the specified fields. URLs are treated like
   // prefixes; other fields are exact matches. Empty strings are not matched to
   // anything. For daysAgo, today is 0, yesterday is 1, etc.; a negative number
   // of days is treated as a missing parameter.
   void GetFilteredActions(
       const std::string& extension_id,
       const Action::ActionType type,
       const std::string& api_name,
       const std::string& page_url,
       const std::string& arg_url,
       const int days_ago,
       const base::Callback<
           void(std::unique_ptr<std::vector<scoped_refptr<Action>>>)>& callback);
 
   // ExtensionRegistryObserver.
   // We keep track of whether the whitelisted extension is installed; if it is,
   // we want to recompute whether to have logging enabled.
   void OnExtensionLoaded(content::BrowserContext* browser_context,
                          const Extension* extension) override;
   void OnExtensionUnloaded(content::BrowserContext* browser_context,
                            const Extension* extension,
                            UnloadedExtensionInfo::Reason reason) override;
   void OnExtensionUninstalled(content::BrowserContext* browser_context,
                               const Extension* extension,
                               extensions::UninstallReason reason) override;
 
-  // ApiActivityMonitor.
-  void OnApiEventDispatched(
-      const std::string& extension_id,
-      const std::string& event_name,
-      std::unique_ptr<base::ListValue> event_args) override;
-  void OnApiFunctionCalled(
-      const std::string& extension_id,
-      const std::string& api_name,
-      std::unique_ptr<base::ListValue> event_args) override;
-
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);
 
   // Remove actions from the activity log database which IDs specified in the
   // action_ids array.
   void RemoveActions(const std::vector<int64_t>& action_ids);
 
   // Clean up URLs from the activity log database.
   // If restrict_urls is empty then all URLs in the activity log database are
   // removed, otherwise only those in restrict_urls are removed.
   void RemoveURLs(const std::vector<GURL>& restrict_urls);
@@ skipping 29 matching lines @@
                          const ExecutingScriptsMap& extension_ids,
                          const GURL& on_url) override;
 
   // At the moment, ActivityLog will use only one policy for summarization.
   // These methods are used to choose and set the most appropriate policy.
   // Changing policies at runtime is not recommended, and likely only should be
   // done for unit tests.
   void ChooseDatabasePolicy();
   void SetDatabasePolicy(ActivityLogPolicy::PolicyType policy_type);
 
+  // Checks the current |is_active_| state and modifies it if appropriate.
+  void CheckActive();
+
+  // content::NotificationObserver:
+  void Observe(int type,
+               const content::NotificationSource& source,
+               const content::NotificationDetails& details) override;
+
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() { return "ActivityLog"; }
   static const bool kServiceRedirectedInIncognito = true;
   static const bool kServiceIsCreatedWithBrowserContext = false;
 
   typedef base::ObserverListThreadSafe<Observer> ObserverList;
   scoped_refptr<ObserverList> observers_;
 
   // Policy objects are owned by the ActivityLog, but cannot be scoped_ptrs
   // since they may need to do some cleanup work on the database thread.
@@ skipping 24 matching lines @@
   // added or removed, enabled_ may change.
   ScopedObserver<extensions::ExtensionRegistry,
                  extensions::ExtensionRegistryObserver>
       extension_registry_observer_;
 
   // Set if the watchdog app is installed and enabled. Maintained by
   // kWatchdogExtensionActive pref variable. Since there are multiple valid
   // extension IDs, this needs to be an int to count how many are installed.
   int watchdog_apps_active_;
 
+  // True if the activity log is currently active.
+  bool is_active_;
+
+  content::NotificationRegistrar registrar_;
+
   FRIEND_TEST_ALL_PREFIXES(ActivityLogApiTest, TriggerEvent);
   FRIEND_TEST_ALL_PREFIXES(ActivityLogEnabledTest, AppAndCommandLine);
   FRIEND_TEST_ALL_PREFIXES(ActivityLogEnabledTest, CommandLineSwitch);
   FRIEND_TEST_ALL_PREFIXES(ActivityLogEnabledTest, NoSwitch);
   FRIEND_TEST_ALL_PREFIXES(ActivityLogEnabledTest, PrefSwitch);
   FRIEND_TEST_ALL_PREFIXES(ActivityLogEnabledTest, WatchdogSwitch);
   DISALLOW_COPY_AND_ASSIGN(ActivityLog);
 };
 
 template <>
 void BrowserContextKeyedAPIFactory<ActivityLog>::DeclareFactoryDependencies();
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_ACTIVITY_LOG_ACTIVITY_LOG_H_