Use a direct include of strings headers in ui/, part 1.

ui/base/accessibility/accessible_view_state.h

 // Copyright (c) 2011 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_BASE_ACCESSIBILITY_ACCESSIBLE_VIEW_STATE_H_
 #define UI_BASE_ACCESSIBILITY_ACCESSIBLE_VIEW_STATE_H_
 
 #include "base/basictypes.h"
-#include "base/string16.h"
+#include "base/strings/string16.h"
 #include "ui/base/accessibility/accessibility_types.h"
 #include "ui/base/ui_export.h"
 
 namespace ui {
 
 ////////////////////////////////////////////////////////////////////////////////
 //
 // AccessibleViewState
 //
 //   A cross-platform struct for storing the core accessibility information
@@ skipping 32 matching lines @@
   // The selected item's index and the count of the number of items.
   // Only applies to views with multiple choices like a listbox; both
   // index and count should be -1 otherwise.
   int index;
   int count;
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_ACCESSIBILITY_ACCESSIBLE_VIEW_STATE_H_