Remove some platform specific stuff from views.

ui/app_list/views/app_list_view_observer.h

Index: ui/app_list/views/app_list_view_observer.h
diff --git a/ui/app_list/views/app_list_view_observer.h b/ui/app_list/views/app_list_view_observer.h
deleted file mode 100644
index f9fb61c819d5780af5f00085a30bc8b8145a5f7e..0000000000000000000000000000000000000000
--- a/ui/app_list/views/app_list_view_observer.h
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_APP_LIST_VIEWS_APP_LIST_VIEW_OBSERVER_H_
-#define UI_APP_LIST_VIEWS_APP_LIST_VIEW_OBSERVER_H_
-
-namespace views {
-class Widget;
-}
-
-namespace app_list {
-
-class AppListViewObserver {
- public:
-  virtual void OnActivationChanged(views::Widget* widget, bool active) = 0;
-
- protected:
-  virtual ~AppListViewObserver() {}
-};
-
-}  // namespace app_list
-
-#endif  // UI_APP_LIST_VIEWS_APP_LIST_VIEW_OBSERVER_H_