[Hotword] Sync Audio History pref every 24 hours, when opening chrome://settings and . . .

chrome/browser/search/hotword_audio_history_handler.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_SEARCH_HOTWORD_AUDIO_HISTORY_HANDLER_H_
 #define CHROME_BROWSER_SEARCH_HOTWORD_AUDIO_HISTORY_HANDLER_H_
 
+#include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/prefs/pref_change_registrar.h"
 #include "content/public/browser/browser_context.h"
 
 class Profile;
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace history {
 class WebHistoryService;
 }
 
 // A class which handles the audio history pref for hotwording. This has been
 // pulled into its own class in order to transparently (to the rest of
 // hotwording) handle changing user global pref management systems.
 class HotwordAudioHistoryHandler {
  public:
   typedef base::Callback<void(bool success, bool new_enabled_value)>
       HotwordAudioHistoryCallback;
 
-  explicit HotwordAudioHistoryHandler(content::BrowserContext* context);
+  HotwordAudioHistoryHandler(
+      content::BrowserContext* context,
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+
   virtual ~HotwordAudioHistoryHandler();
 
+  // Initiates a call to get the updated audio history state.
+  void UpdateAudioHistoryState();
+
   // Updates the current preference value based on the user's account info
   // or false if the user is not signed in.
-  void GetAudioHistoryEnabled(const HotwordAudioHistoryCallback& callback);
+  virtual void GetAudioHistoryEnabled(
+      const HotwordAudioHistoryCallback& callback);
 
   // Sets the user's global pref value for enabling audio history.
   void SetAudioHistoryEnabled(const bool enabled,
                               const HotwordAudioHistoryCallback& callback);
 
   // This helper function is made public for testing.
   virtual history::WebHistoryService* GetWebHistory();
 
  private:
+  // Helper function used as a callback and to factor out common code.
+  void UpdateLocalPreference(bool success, bool new_enabled_value);
+
   // Called upon completion of web history->GetAudioHistoryEnabled.
   void GetAudioHistoryComplete(
       const HotwordAudioHistoryCallback& callback,
       bool success,
       bool new_enabled_value);
 
   // Called upon completion of web history->SetAudioHistoryEnabled.
   // |new_enabled_value| is the desired value of the preference.
   // |callback_enabled_value| should not be considered valid.
   void SetAudioHistoryComplete(
       bool new_enabled_value,
       const HotwordAudioHistoryCallback& callback,
       bool success,
       bool callback_enabled_value);
 
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
   Profile* profile_;
 
   base::WeakPtrFactory<HotwordAudioHistoryHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HotwordAudioHistoryHandler);
 };
 
 #endif  // CHROME_BROWSER_SEARCH_HOTWORD_AUDIO_HISTORY_HANDLER_H_