Exclude host-side code from the NaCl IRT proxy build.

ppapi/proxy/ppp_instance_proxy.cc

Index: ppapi/proxy/ppp_instance_proxy.cc
===================================================================
--- ppapi/proxy/ppp_instance_proxy.cc	(revision 167150)
+++ ppapi/proxy/ppp_instance_proxy.cc	(working copy)
@@ -28,6 +28,7 @@
 
 namespace {
 
+#if !defined(OS_NACL)
 PP_Bool IsFlashFullscreen(PP_Instance instance,
                           HostDispatcher* dispatcher) {
   const PPB_FlashFullscreen* flash_fullscreen_interface =
@@ -119,6 +120,7 @@
   &DidChangeFocus,
   &HandleDocumentLoad
 };
+#endif  // !defined(OS_NACL)
 
 }  // namespace
 
@@ -142,10 +144,12 @@
 PPP_Instance_Proxy::~PPP_Instance_Proxy() {
 }
 
+#if !defined(OS_NACL)
 // static
 const PPP_Instance* PPP_Instance_Proxy::GetInstanceInterface() {
   return &instance_interface;
 }
+#endif  // !defined(OS_NACL)
 
 bool PPP_Instance_Proxy::OnMessageReceived(const IPC::Message& msg) {
   bool handled = true;