cros: Fix various small issues with cast tray entry.

ash/ash_strings.grd

Index: ash/ash_strings.grd
diff --git a/ash/ash_strings.grd b/ash/ash_strings.grd
index 4a366cf13740a8eca55edd781a6d816401a75ad2..758f3b8e6a4a073e361c2936cba98456d8ebae24 100644
--- a/ash/ash_strings.grd
+++ b/ash/ash_strings.grd
@@ -223,6 +223,7 @@ Press Ctrl+Alt+Z to disable.
       <message name="IDS_ASH_STATUS_TRAY_CAST" desc="The label used as the header in the cast popup.">
         Cast screen
       </message>
+      <!-- Keep these aligned with the STOP_CAST_* strings below -->
       <message name="IDS_ASH_STATUS_TRAY_CAST_CAST_DESKTOP" desc="The label used in the tray popup to tell the user we are casting the desktop.">
         Casting screen to <ph name="RECEIVER_NAME">$1<ex>Living Room</ex></ph>
       </message>
@@ -244,6 +245,16 @@ Press Ctrl+Alt+Z to disable.
       <message name="IDS_ASH_STATUS_TRAY_CAST_STOP" desc="The label used in the tray popup to stop casting.">
         Stop
       </message>
+      <!-- Keep these aligned with the CAST_* strings above -->
+      <message name="IDS_ASH_STATUS_TRAY_CAST_STOP_CAST_DESKTOP_ACCESSIBILITY" desc="Stop button accessibility label used in the tray popup to tell the user to stop a cast to the desktop.">
+        Stop casting screen to <ph name="RECEIVER_NAME">$1<ex>Living Room</ex></ph>
+      </message>
+      <message name="IDS_ASH_STATUS_TRAY_CAST_STOP_CAST_TAB_ACCESSIBILITY" desc="Stop button accessibility label used in the tray popup to tell the user to stop a tab cast.">
+        Stop casting <ph name="TAB_NAME">$1<ex>YouTube</ex></ph> to <ph name="RECEIVER_NAME">$2<ex>Living Room</ex></ph>
+      </message>
+      <message name="IDS_ASH_STATUS_TRAY_CAST_STOP_CAST_UNKNOWN_ACCESSIBILITY" desc="Stop button accessibility label used in the tray popup to tell the user to stop a cast, but we do not know what we are casting or who we are casting to.">
+        Stop casting to an unknown receiver
+      </message>

[stevenjb, 2017/01/28 01:05:46]

nit: I think it might actually be easier to maintain if we interleave the _STOP
strings with the other strings, and name them e.g.
IDS_ASH_STATUS_TRAY_CAST_CAST_DESKTOP_ACCESSIBILITY_STOP

[jdufault, 2017/01/28 01:15:37]

Done; I was considering interleaving but didn't consider adding STOP as a
postfix.

 
       <message name="IDS_ASH_STATUS_TRAY_BLUETOOTH" desc="The label used as the header in the bluetooth popup.">
         Bluetooth