a11y: Add a11y information to views::Tab and manually ignore its a11y children.

ui/strings/ui_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 app/ that
 need to be translated for each locale.-->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
     <!-- TODO add each of your output files.  Modify the three below, and add
@@ skipping 326 matching lines @@
         press
       </message>
       <message name="IDS_AX_SELECT_ACTION_VERB" desc="Verb stating the action that will occur when an element such as a radio button is selected, as used by accessibility.">
         select
       </message>
       <message name="IDS_AX_UNCHECK_ACTION_VERB" desc="Verb stating the action that will occur when a checked checkbox is clicked, as used by accessibility.">
         uncheck
       </message>
 
       <!--Accessible name strings-->
+      <if expr="is_macosx">
+        <message name="IDS_ACCNAME_TAB_ROLE_DESCRIPTION" desc="A generic description of a tab button's role." meaning="UI element">
+          Tab
+        </message>
+      </if>
       <message name="IDS_APP_ACCNAME_CLOSE" desc="The accessible name for the Close button.">
         Close
       </message>
       <message name="IDS_APP_ACCNAME_MINIMIZE" desc="The accessible name for the Minimize button.">
         Minimize
       </message>
       <message name="IDS_APP_ACCNAME_MAXIMIZE" desc="The accessible name for the Maximize button.">
         Maximize
       </message>
       <message name="IDS_APP_ACCNAME_RESTORE" desc="The accessible name for the Restore button.">
@@ skipping 311 matching lines @@
       </message>
       <message name="IDS_DISPLAY_NAME_INTERNAL" desc="The name used for internal displays, which is shown in the display settings.">
         Internal Display
       </message>
       <message name="IDS_DISPLAY_NAME_VIRTUAL" desc="The name used for virtual displays, which is shown in the display settings. Virtual displays are not associated with a physical monitor.">
         Virtual Display
       </message>
     </messages>
   </release>
 </grit>