Take extensions out of Profile into a profile-keyed service, ExtensionSystem.

chrome/browser/profiles/profile_io_data.cc

Index: chrome/browser/profiles/profile_io_data.cc
diff --git a/chrome/browser/profiles/profile_io_data.cc b/chrome/browser/profiles/profile_io_data.cc
index 0df44a96e3e8a092cfc5a6efc9c3374dc9b06dac..03a2c871498b954433e4b43feb4b449ef383bc52 100644
--- a/chrome/browser/profiles/profile_io_data.cc
+++ b/chrome/browser/profiles/profile_io_data.cc
@@ -23,6 +23,8 @@
 #include "chrome/browser/download/download_service_factory.h"
 #include "chrome/browser/extensions/extension_info_map.h"
 #include "chrome/browser/extensions/extension_protocols.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/extensions/extension_system_factory.h"
 #include "chrome/browser/io_thread.h"
 #include "chrome/browser/media/media_internals.h"
 #include "chrome/browser/net/chrome_cookie_notification_details.h"
@@ -227,7 +229,8 @@ void ProfileIOData::InitializeOnUIThread(Profile* profile) {
                  profile);
   params->cookie_monster_delegate =
       new ChromeCookieMonsterDelegate(profile_getter);
-  params->extension_info_map = profile->GetExtensionInfoMap();
+  params->extension_info_map =
+      ExtensionSystemFactory::GetForProfile(profile)->info_map();
   params->notification_service =
       DesktopNotificationServiceFactory::GetForProfile(profile);
   params->protocol_handler_registry = profile->GetProtocolHandlerRegistry();