Add a skeleton gamepad resource.

ppapi/thunk/ppb_gamepad_thunk.cc

Index: ppapi/thunk/ppb_gamepad_thunk.cc
diff --git a/ppapi/thunk/ppb_gamepad_thunk.cc b/ppapi/thunk/ppb_gamepad_thunk.cc
index 61b3195abbb585cca4112e256357f6b7caeedb3c..3aeedb57dea12d116e6b0f112e98327f5ff1510b 100644
--- a/ppapi/thunk/ppb_gamepad_thunk.cc
+++ b/ppapi/thunk/ppb_gamepad_thunk.cc
@@ -2,9 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <string.h>
+
 #include "ppapi/c/ppb_gamepad.h"
 #include "ppapi/thunk/thunk.h"
 #include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/ppb_gamepad_api.h"
 #include "ppapi/thunk/ppb_instance_api.h"
 #include "ppapi/thunk/resource_creation_api.h"
 
@@ -15,9 +18,15 @@ namespace {
 
 void SampleGamepads(PP_Instance instance, PP_GamepadsSampleData* data) {
   EnterInstance enter(instance);
-  if (enter.failed())
-    return;
-  enter.functions()->SampleGamepads(instance, data);
+  if (enter.succeeded()) {
+    PPB_Gamepad_API* api = enter.functions()->GetGamepadAPI(instance);
+    if (api) {
+      api->Sample(data);
+      return;
+    }
+  }
+  // Failure, zero out.
+  memset(data, 0, sizeof(PP_GamepadsSampleData));
 }
 
 const PPB_Gamepad g_ppb_gamepad_thunk = {