Add the Copresence API.

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index fbb5fa3a650ae84fa435d0cbf5473488dc18eb58..c11bdce44a0f9b3baddf64560d0d604a9a5b9161 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -112,6 +112,7 @@
 #include "apps/prefs.h"
 #include "chrome/browser/extensions/activity_log/activity_log.h"
 #include "chrome/browser/extensions/api/commands/command_service.h"
+#include "chrome/browser/extensions/api/copresence/copresence_api.h"
 #include "chrome/browser/extensions/api/tabs/tabs_api.h"
 #include "chrome/browser/extensions/launch_util.h"
 #include "chrome/browser/signin/easy_unlock_service.h"
@@ -273,6 +274,10 @@ void RegisterLocalState(PrefRegistrySimple* registry) {
   policy::PolicyStatisticsCollector::RegisterPrefs(registry);
 #endif
 
+#if defined(ENABLE_EXTENSIONS)
+  extensions::CopresenceService::RegisterPrefs(registry);
+#endif
+
 #if defined(ENABLE_NOTIFICATIONS) && !defined(OS_ANDROID)
   // Android does not use the message center for notifications.
   MessageCenterNotificationManager::RegisterPrefs(registry);