Expose correct semantics for HTML5 footer element on mac and windows platforms, as per https://bugs…

webkit/glue/webkit_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- This file contains definitions of resources that will be translated for
 each locale. Specifically, these are UI strings that are used by webkit that
 need to be translated for each locale.-->
 
 <!-- Some of these strings and string descriptions were taken from
 WebKit/win/WebCoreLocalizedStrings.cpp so we include the original license
 below:
 
@@ skipping 255 matching lines @@
       </message>
       <message name="IDS_AX_ROLE_LIST_MARKER" desc="accessibility role description for list marker">
         list marker
       </message>
       <message name="IDS_AX_ROLE_IMAGE_MAP" desc="accessibility role description for image map">
         image map
       </message>
       <message name="IDS_AX_ROLE_HEADING" desc="accessibility role description for headings">
         heading
       </message>
+      <message name="IDS_AX_ROLE_FOOTER" desc="accessibility role description for footers">
+        footer
+      </message>
 
       <message name="IDS_AX_BUTTON_ACTION_VERB" desc="Verb stating the action that will occur when a button is pressed, as used by accessibility.">
         press
       </message>
       <message name="IDS_AX_RADIO_BUTTON_ACTION_VERB" desc="Verb stating the action that will occur when a radio button is clicked, as used by accessibility.">
         select
       </message>
       <message name="IDS_AX_TEXT_FIELD_ACTION_VERB" desc="Verb stating the action that will occur when a text field is selected, as used by accessibility.">
         activate
       </message>
@@ skipping 117 matching lines @@
         Failed to load PDF document
       </message>
 
       <message name="IDS_PDF_PROGRESS_LOADING" desc="A message displayed on the progress control over PDF page during document loading.">
         Loading
       </message>
       
     </messages>
   </release>
 </grit>