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

chrome/browser/ui/webui/options/browser_options_handler.h

Index: chrome/browser/ui/webui/options/browser_options_handler.h
diff --git a/chrome/browser/ui/webui/options/browser_options_handler.h b/chrome/browser/ui/webui/options/browser_options_handler.h
index 6bfd46a5ac979aa5aae1eea930a01bc2b9dbbe66..d6c99e5b4a45a8a0d5ed7c1ae215234a9da91faa 100644
--- a/chrome/browser/ui/webui/options/browser_options_handler.h
+++ b/chrome/browser/ui/webui/options/browser_options_handler.h
@@ -285,6 +285,14 @@ class BrowserOptionsHandler
   // the hotword section of the settings page.
   void SendHotwordAvailable();
 
+  // Callback that updates the visibility of the audio history upon completion
+  // of a call to the server to the get the current value.
+  void SetHotwordAudioHistorySectionVisible(
+      bool always_on,
+      const base::string16& audio_history_state,
+      bool success,
+      bool logging_enabled);
+
   // Callback for "requestHotwordAvailable" message.
   void HandleRequestHotwordAvailable(const base::ListValue* args);