Add an accessibility role for the iframe element (re-land).

Source/web/AssertMatchingEnums.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 181 matching lines @@
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleDocument, DocumentRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleDrawer, DrawerRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleEditableText, EditableTextRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleFooter, FooterRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleForm, FormRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleGrid, GridRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleGroup, GroupRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleGrowArea, GrowAreaRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleHeading, HeadingRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleHelpTag, HelpTagRole);
+COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleIframe, IframeRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleIgnored, IgnoredRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleImageMapLink, ImageMapLinkRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleImageMap, ImageMapRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleImage, ImageRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleIncrementor, IncrementorRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleInlineTextBox, InlineTextBoxRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleLabel, LabelRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleLegend, LegendRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleLink, LinkRole);
 COMPILE_ASSERT_MATCHING_ENUM(WebAXRoleListBoxOption, ListBoxOptionRole);
@@ skipping 393 matching lines @@
 COMPILE_ASSERT_MATCHING_ENUM(WebCustomHandlersRegistered, NavigatorContentUtilsClient::CustomHandlersRegistered);
 COMPILE_ASSERT_MATCHING_ENUM(WebCustomHandlersDeclined, NavigatorContentUtilsClient::CustomHandlersDeclined);
 
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionNone, TouchActionNone);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionAuto, TouchActionAuto);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionPanX, TouchActionPanX);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionPanY, TouchActionPanY);
 COMPILE_ASSERT_MATCHING_ENUM(WebTouchActionPinchZoom, TouchActionPinchZoom);
 
 COMPILE_ASSERT_MATCHING_UINT64(kSerializedScriptValueVersion, SerializedScriptValue::wireFormatVersion);