Use macros to define pepper interfaces

ppapi/proxy/ppp_instance_proxy.h

Index: ppapi/proxy/ppp_instance_proxy.h
diff --git a/ppapi/proxy/ppp_instance_proxy.h b/ppapi/proxy/ppp_instance_proxy.h
index f9b471c40fa936101f28d10963008d3fe9eca782..7b702454896becedb5b9f3a1a194f844822491a4 100644
--- a/ppapi/proxy/ppp_instance_proxy.h
+++ b/ppapi/proxy/ppp_instance_proxy.h
@@ -25,12 +25,7 @@ class SerializedVarReturnValue;
 
 class PPP_Instance_Proxy : public InterfaceProxy {
  public:
-  template <class PPP_Instance_Type>
-  PPP_Instance_Proxy(Dispatcher* dispatcher,
-                     const PPP_Instance_Type* target_interface)
-      : InterfaceProxy(dispatcher, static_cast<const void*>(target_interface)),
-        combined_interface_(new PPP_Instance_Combined(*target_interface)) {
-  }
+  PPP_Instance_Proxy(Dispatcher* dispatcher);
   virtual ~PPP_Instance_Proxy();
 
   // Return the info for the 1.0 (latest, canonical) version of the interface.