Remove DisplayChangeObserver ash dependencies.

ash/ash_strings.grd

Index: ash/ash_strings.grd
diff --git a/ash/ash_strings.grd b/ash/ash_strings.grd
index 36331a203fc33f8d2598b4a318407e5c0756f9f1..628377cbce7985aa03af3c0cbdcaa879ed09b275 100644
--- a/ash/ash_strings.grd
+++ b/ash/ash_strings.grd
@@ -285,9 +285,6 @@ Press Ctrl+Alt+Z to disable.
         Mute
       </message>
 
-      <message name="IDS_ASH_STATUS_TRAY_UNKNOWN_DISPLAY_NAME" desc="Label shown in tray for a display whose name is unknown.">
-        Unknown Display
-      </message>
       <message name="IDS_ASH_STATUS_TRAY_DRIVE" desc="The label used for Google Drive tray details header.">
         Google Drive
       </message>
@@ -402,12 +399,6 @@ Press Ctrl+Alt+Z to disable.
       <message name="IDS_ASH_NOTIFICATION_UNREAD_COUNT_NINE_PLUS" desc="The text shown in the notification icon for the unread count when the count is more than 9.">
         9+
       </message>
-      <message name="IDS_ASH_INTERNAL_DISPLAY_NAME" desc="The name used for internal displays, which is shown in the display settings.">
-        Internal Display
-      </message>
-      <message name="IDS_ASH_VIRTUAL_DISPLAY_NAME" 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>
       <message name="IDS_ASH_EXIT_WARNING_POPUP_TEXT" desc="The text of the popup when the user preses the exit shortcut.">
         Press Ctrl+Shift+Q twice to quit.
       </message>