AX: Add accessibility label strings for calendar picker.

content/app/strings/content_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 content 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 304 matching lines @@
       <message name="IDS_RECENT_SEARCHES_NONE" desc="Label for only item in menu that appears when clicking on the search field image, when no searches have been performed">
         No recent searches
       </message>
       <message name="IDS_RECENT_SEARCHES" desc="label for first item in the menu that appears when clicking on the search field image, used as embedded menu title">
         Recent Searches
       </message>
       <message name="IDS_RECENT_SEARCHES_CLEAR" desc="menu item in Recent Searches menu that empties menu's contents">
         Clear Recent Searches
       </message>
 
+      <message name="IDS_AX_CALENDAR_SHOW_MONTH_SELECTOR" desc="Accessible description of a button to show month selection panel in a calendar picker.">
+        Show month selection panel
+      </message>
+      <message name="IDS_AX_CALENDAR_SHOW_NEXT_MONTH" desc="Accessible description of a button to show next month in a calendar picker.">
+        Show next month
+      </message>
+      <message name="IDS_AX_CALENDAR_SHOW_PREVIOUS_MONTH" desc="Accessible description of a button to show previous month in a calendar picker.">
+        Show previous month
+      </message>
+
       <message name="IDS_AX_ROLE_WEB_AREA" desc="accessibility role description for web area">
         HTML content
       </message>
       <message name="IDS_AX_ROLE_LINK" desc="accessibility role description for link">
         link
       </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">
@@ skipping 330 matching lines @@
         Please shorten this text to <ph name="MAX_CHARACTERS">$2<ex>100</ex></ph> characters or less (you are currently using <ph name="CURRENT_LENGTH">$1<ex>101</ex></ph> characters).
       </message>
 
       <message name="IDS_PLUGIN_INITIALIZATION_ERROR" desc="A message displayed when a plug-in failed to load">
         Couldn't load plug-in.
       </message>
 
     </messages>
   </release>
 </grit>