Split ExtensionSystem interface from ExtensionSystemImpl implementation, part 1.

chrome/browser/extensions/api/dial/dial_api.cc

Index: chrome/browser/extensions/api/dial/dial_api.cc
diff --git a/chrome/browser/extensions/api/dial/dial_api.cc b/chrome/browser/extensions/api/dial/dial_api.cc
index c5416d2ff542f5fbca8a98b84f98eafe79914f04..5339c169c8891331893f840adef441003d5a37c4 100644
--- a/chrome/browser/extensions/api/dial/dial_api.cc
+++ b/chrome/browser/extensions/api/dial/dial_api.cc
@@ -8,11 +8,11 @@
 
 #include "base/time/time.h"
 #include "chrome/browser/extensions/api/dial/dial_api_factory.h"
-#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/api/dial.h"
 #include "content/public/browser/browser_thread.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_system.h"
 
 using base::TimeDelta;
 using content::BrowserThread;