Switch to using the new Link Doctor API.

chrome/browser/prefs/browser_prefs.cc

Index: chrome/browser/prefs/browser_prefs.cc
===================================================================
--- chrome/browser/prefs/browser_prefs.cc	(revision 249692)
+++ chrome/browser/prefs/browser_prefs.cc	(working copy)
@@ -73,9 +73,9 @@
 #include "chrome/browser/sync/sync_prefs.h"
 #include "chrome/browser/task_manager/task_manager.h"
 #include "chrome/browser/translate/translate_prefs.h"
-#include "chrome/browser/ui/alternate_error_tab_observer.h"
 #include "chrome/browser/ui/app_list/app_list_service.h"
 #include "chrome/browser/ui/browser_ui_prefs.h"
+#include "chrome/browser/ui/link_doctor_tab_observer.h"
 #include "chrome/browser/ui/network_profile_bubble.h"
 #include "chrome/browser/ui/prefs/prefs_tab_helper.h"
 #include "chrome/browser/ui/search_engines/keyword_editor_controller.h"
@@ -330,7 +330,6 @@
 void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   TRACE_EVENT0("browser", "chrome::RegisterUserPrefs");
   // User prefs. Please keep this list alphabetized.
-  AlternateErrorPageTabObserver::RegisterProfilePrefs(registry);
   apps::RegisterProfilePrefs(registry);
   autofill::AutofillManager::RegisterProfilePrefs(registry);
   BookmarkPromptPrefs::RegisterProfilePrefs(registry);
@@ -347,6 +346,7 @@
   HostContentSettingsMap::RegisterProfilePrefs(registry);
   IncognitoModePrefs::RegisterProfilePrefs(registry);
   InstantUI::RegisterProfilePrefs(registry);
+  LinkDoctorTabObserver::RegisterProfilePrefs(registry);
   MediaCaptureDevicesDispatcher::RegisterProfilePrefs(registry);
   MediaDeviceIDSalt::RegisterProfilePrefs(registry);
   MediaStreamDevicesController::RegisterProfilePrefs(registry);