Bug 1198084 - Add strings for tab playing audio. r=mhaigh

--HG--
extra : commitid : 9x88jYLwf27
extra : rebase_source : dc2677a66f6b638afcd80de9d4cdd4e8785ae5fe

mobile/android/base/locales/en-US/android_strings.dtd

@@ -80,6 +80,14 @@
      as possible because it's shown as a label in a toast.  Ideally, this string
      is upper-case, to match Google and Android's convention. -->
 <!ENTITY switch_button_message "SWITCH">
+<!-- Localization note (tab_title_prefix_is_playing_audio): This string is not
+     visible in the UI, but rather used as a text-to-speech content description
+     for sight-impaired a11y users. The content description is set on a tab
+     title in a list of open tabs when content in that tab is playing audio.
+     &formatS; will be replaced with the title of the tab, as received from the
+     web page. When audio is not playing in a tab, &formatS; will be used as
+     the content description. -->
+<!ENTITY tab_title_prefix_is_playing_audio "Playing audio – &formatS;">
 
 <!ENTITY settings "Settings">
 <!ENTITY settings_title "Settings">

mobile/android/base/strings.xml.in

@@ -315,6 +315,7 @@
   <string name="new_tab_opened">&new_tab_opened;</string>
   <string name="new_private_tab_opened">&new_private_tab_opened;</string>
   <string name="switch_button_message">&switch_button_message;</string>
+  <string name="tab_title_prefix_is_playing_audio">&tab_title_prefix_is_playing_audio;</string>
   <string name="one_tab">&one_tab;</string>
   <string name="num_tabs">&num_tabs2;</string>
   <string name="addons">&addons;</string>