Mojo: Fix MojoReadMessage() with *num_handles == 0.

R=davemoore@chromium.org, davemoore

Review URL: https://codereview.chromium.org/75243005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@235837 0039d316-1c4b-4281-b951-d872f2087c98

mojo/system/core_impl.cc

@@ -322,7 +322,7 @@ MojoResult CoreImpl::ReadMessage(
 
   // Easy case: won't receive any handles.
   if (!num_handles || *num_handles == 0)
-    return dispatcher->ReadMessage(bytes, num_bytes, 0, NULL, flags);
+    return dispatcher->ReadMessage(bytes, num_bytes, NULL, num_handles, flags);
 
   std::vector<scoped_refptr<Dispatcher> > dispatchers;
   MojoResult rv = dispatcher->ReadMessage(bytes, num_bytes,