Remove some InterfacePtr<> methods which directly deal with message pipe handles.

sky/viewer/internals.cc

Index: sky/viewer/internals.cc
diff --git a/sky/viewer/internals.cc b/sky/viewer/internals.cc
index cda73c1254c19512738a842328fea69f6915444e..1a322669e01e9219b640378a3df4428520de1994 100644
--- a/sky/viewer/internals.cc
+++ b/sky/viewer/internals.cc
@@ -172,7 +172,7 @@ mojo::Handle Internals::TakeShellProxyHandle() {
   mojo::ShellPtr shell;
   if (!shell_binding_.is_bound())
     shell_binding_.Bind(GetProxy(&shell));
-  return shell.PassMessagePipe().release();
+  return shell.PassInterface().PassHandle().release();
 }
 
 void Internals::ConnectToApplication(