Merge "Document linkToDeath behavior on object cleanup." am: ef92508f70

Change-Id: I608c0108c49f909cc81c2a6a4837eb36466e6a09
diff --git a/libs/binder/include/binder/IBinder.h b/libs/binder/include/binder/IBinder.h
index 64604b7..eea0e89 100644
--- a/libs/binder/include/binder/IBinder.h
+++ b/libs/binder/include/binder/IBinder.h
@@ -173,6 +173,10 @@
      * The @a cookie is optional -- if non-NULL, it should be a
      * memory address that you own (that is, you know it is unique).
      *
+     * @note When all references to the binder being linked to are dropped, the
+     * recipient is automatically unlinked. So, you must hold onto a binder in
+     * order to receive death notifications about it.
+     *
      * @note You will only receive death notifications for remote binders,
      * as local binders by definition can't die without you dying as well.
      * Trying to use this function on a local binder will result in an