Content description for appcompat action mode done buttons

Bug 17649032

Change-Id: Ic1799e7bd171621d0d1eada23b2633dfe0a20a16
diff --git a/v7/appcompat/res/layout/abc_action_mode_close_item_material.xml b/v7/appcompat/res/layout/abc_action_mode_close_item_material.xml
index a82aebf..dfc4deb 100644
--- a/v7/appcompat/res/layout/abc_action_mode_close_item_material.xml
+++ b/v7/appcompat/res/layout/abc_action_mode_close_item_material.xml
@@ -17,6 +17,7 @@
 <android.support.v7.internal.widget.TintImageView
              xmlns:android="http://schemas.android.com/apk/res/android"
              android:id="@+id/action_mode_close_button"
+             android:contentDescription="@string/abc_action_mode_done"
              android:focusable="true"
              android:clickable="true"
              android:src="?attr/actionModeCloseDrawable"