Implemented the "aria-current" state on Windows.

ui/accessibility/ax_tree_combiner.cc

 // Copyright 2016 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.
 
 #include "ui/accessibility/ax_tree.h"
 #include "ui/accessibility/ax_tree_combiner.h"
 #include "ui/gfx/geometry/rect_f.h"
 
 namespace ui {
 namespace {
@@ skipping 32 matching lines @@
     case AX_ATTR_TABLE_CELL_ROW_INDEX:
     case AX_ATTR_TABLE_CELL_ROW_SPAN:
     case AX_ATTR_SORT_DIRECTION:
     case AX_ATTR_HIERARCHICAL_LEVEL:
     case AX_ATTR_NAME_FROM:
     case AX_ATTR_DESCRIPTION_FROM:
     case AX_ATTR_CHILD_TREE_ID:
     case AX_ATTR_SET_SIZE:
     case AX_ATTR_POS_IN_SET:
     case AX_ATTR_COLOR_VALUE:
+    case AX_ATTR_ARIA_CURRENT_STATE:
     case AX_ATTR_BACKGROUND_COLOR:
     case AX_ATTR_COLOR:
     case AX_ATTR_INVALID_STATE:
     case AX_ATTR_TEXT_DIRECTION:
     case AX_ATTR_TEXT_STYLE:
       return false;
   }
 
   NOTREACHED();
   return false;
@@ skipping 166 matching lines @@
     // Recurse into the child tree now, if any.
     if (child_tree)
       ProcessTree(child_tree);
   }
 
   // Reset the transform.
   transform_ = old_transform;
 }
 
 }  // namespace ui