Move ExtensionPrefs and friends to extensions/ directory.

chrome/browser/extensions/extension_toolbar_model.h

Index: chrome/browser/extensions/extension_toolbar_model.h
diff --git a/chrome/browser/extensions/extension_toolbar_model.h b/chrome/browser/extensions/extension_toolbar_model.h
index ac8aec7f9c707ac8b6753f43e9fcb17e4ff634d3..f64bc836580c61c03c31e4e98bbb857fc96942c4 100644
--- a/chrome/browser/extensions/extension_toolbar_model.h
+++ b/chrome/browser/extensions/extension_toolbar_model.h
@@ -8,10 +8,10 @@
 #include "base/compiler_specific.h"
 #include "base/observer_list.h"
 #include "base/prefs/pref_change_registrar.h"
-#include "chrome/browser/extensions/extension_prefs.h"
 #include "components/browser_context_keyed_service/browser_context_keyed_service.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "extensions/browser/extension_prefs.h"
 #include "extensions/common/extension.h"
 
 class Browser;
@@ -21,7 +21,7 @@ class Profile;
 
 // Model for the browser actions toolbar.
 class ExtensionToolbarModel : public content::NotificationObserver,
-                              public BrowserContextKeyedService   {
+                              public BrowserContextKeyedService {
  public:
   ExtensionToolbarModel(Profile* profile,
                         extensions::ExtensionPrefs* extension_prefs);