Implement the gamepad API in the IPC proxy

content/browser/gamepad/gamepad_platform_data_fetcher.cc

+// 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.
+
+#include "content/browser/gamepad/gamepad_platform_data_fetcher.h"
+
+#include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebGamepads.h"
+
+namespace content {
+
+GamepadDataFetcherEmpty::GamepadDataFetcherEmpty() {
+}
+
+void GamepadDataFetcherEmpty::GetGamepadData(WebKit::WebGamepads* pads,
+                                             bool devices_changed_hint) {
+  pads->length = 0;
+}
+
+}  // namespace content