Remove extension-to-component migration mechanism

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 f28f1ce5b8218fb6fc41ecfb58a6f0a71afb46f8..894c9b7d699487209dd96eb1fa6867e48d8fb185 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -128,7 +128,6 @@
 #include "chrome/browser/extensions/activity_log/activity_log.h"
 #include "chrome/browser/extensions/api/commands/command_service.h"
 #include "chrome/browser/extensions/api/tabs/tabs_api.h"
-#include "chrome/browser/extensions/component_migration_helper.h"
 #include "chrome/browser/extensions/extension_web_ui.h"
 #include "chrome/browser/extensions/launch_util.h"
 #include "chrome/browser/signin/easy_unlock_service.h"
@@ -532,7 +531,6 @@ void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
   RegisterAnimationPolicyPrefs(registry);
   ToolbarActionsBar::RegisterProfilePrefs(registry);
   extensions::ActivityLog::RegisterProfilePrefs(registry);
-  extensions::ComponentMigrationHelper::RegisterPrefs(registry);
   extensions::ExtensionPrefs::RegisterProfilePrefs(registry);
   extensions::launch_util::RegisterProfilePrefs(registry);
   extensions::RuntimeAPI::RegisterPrefs(registry);