Add a skeleton gamepad resource.

ppapi/host/dispatch_host_message.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file provides infrastructure for dispatching host resource call
 // messages. Normal IPC message handlers can't take extra parameters or
 // return values. We want to take a HostMessageContext as a parameter and
 // also return the int32_t return value to the caller.
 
 #ifndef PPAPI_HOST_DISPATCH_HOST_MESSAGE_H_
@@ skipping 43 matching lines @@
   return (obj->*method)(context, arg.a, arg.b, arg.c, arg.d);
 }
 
 template<class ObjT, class Method, class A, class B, class C, class D, class E>
 inline int32_t DispatchResourceCall(ObjT* obj, Method method,
                                     HostMessageContext* context,
                                     const Tuple5<A, B, C, D, E>& arg) {
   return (obj->*method)(context, arg.a, arg.b, arg.c, arg.d, arg.e);
 }
 
+// Note that this only works for message with 1 or more parameters. For
+// 0-parameter messages you need to use the _0 version below (since there are
+// no Params in the message).
 #define PPAPI_DISPATCH_HOST_RESOURCE_CALL(msg_class, member_func) \
     case msg_class::ID: { \
-        TRACK_RUN_IN_IPC_HANDLER(member_func); \
-        msg_class::Schema::Param p; \
-        if (msg_class::Read(&ipc_message__, &p)) { \
-          return ppapi::host::DispatchResourceCall( \
-              this, \
-              &_IpcMessageHandlerClass::member_func, \
-              context, p); \
-        } else { \
-          return PP_ERROR_FAILED; \
-        }  \
-      }  \
-      break;
+      TRACK_RUN_IN_IPC_HANDLER(member_func); \
+      msg_class::Schema::Param p; \
+      if (msg_class::Read(&ipc_message__, &p)) { \
+        return ppapi::host::DispatchResourceCall( \
+            this, \
+            &_IpcMessageHandlerClass::member_func, \
+            context, p); \
+      } \
+      return PP_ERROR_FAILED; \
+    }
+
+#define PPAPI_DISPATCH_HOST_RESOURCE_CALL_0(msg_class, member_func) \
+  case msg_class::ID: { \
+      TRACK_RUN_IN_IPC_HANDLER(member_func); \
+      return member_func(context); \
+    }
+
 
 }  // namespace host
 }  // namespace ppapi
 
 #endif  // PPAPI_HOST_DISPATCH_HOST_MESSAGE_H_