Added non-prefixed navigator.getGamepads() with updated API

Source/modules/gamepad/GamepadButton.cpp

Index: Source/modules/gamepad/GamepadButton.cpp
diff --git a/Source/modules/gamepad/GamepadButton.cpp b/Source/modules/gamepad/GamepadButton.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..97faaa51014b1f5e73f079e90fd090c82c383ed2
--- /dev/null
+++ b/Source/modules/gamepad/GamepadButton.cpp
@@ -0,0 +1,30 @@
+// 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 {
+
+PassRefPtrWillBeRawPtr<GamepadButton> GamepadButton::create()
+{
+    return adoptRefWillBeNoop(new GamepadButton());
+}
+
+GamepadButton::GamepadButton()
+    : m_value(0.f)
+    , m_pressed(false)
+{
+    ScriptWrappable::init(this);
+}
+
+GamepadButton::~GamepadButton()
+{
+}
+
+void GamepadButton::trace(Visitor* visitor)
+{
+}
+
+} // namespace WebCore