Updating Blink-side WebGamepad interface

Source/modules/gamepad/GamepadButton.cpp

+// Copyright 2014 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 "config.h"
+#include "modules/gamepad/Gamepad.h"
+
+namespace WebCore {
+
+PassRefPtr<GamepadButton> GamepadButton::create()
+{
+    RefPtr<GamepadButton> input = adoptRef(new GamepadButton());
+    return input.release();
+}
+
+GamepadButton::GamepadButton()
+    : m_value(0.f)
+    , m_pressed(false)
+{
+    ScriptWrappable::init(this);
+}
+
+GamepadButton::~GamepadButton()
+{
+}
+
+} // namespace WebCore