Factor out GamepadCommon base class from Gamepad and WebKitGamepad

Source/modules/gamepad/Gamepad.cpp

Index: Source/modules/gamepad/Gamepad.cpp
diff --git a/Source/modules/gamepad/Gamepad.cpp b/Source/modules/gamepad/Gamepad.cpp
index 499e97bf49bc618b51fdb1a908a2d8f4385be5f9..6d547adda0829851026bc4a8c8f8b0e50c883906 100644
--- a/Source/modules/gamepad/Gamepad.cpp
+++ b/Source/modules/gamepad/Gamepad.cpp
@@ -28,20 +28,6 @@
 
 namespace WebCore {
 
-Gamepad::Gamepad()
-    : m_index(0)
-    , m_timestamp(0)
-{
-    ScriptWrappable::init(this);
-}
-
-void Gamepad::setAxes(unsigned count, const float* data)
-{
-    m_axes.resize(count);
-    if (count)
-        std::copy(data, data + count, m_axes.begin());
-}
-
 void Gamepad::setButtons(unsigned count, const blink::WebGamepadButton* data)
 {
     if (m_buttons.size() != count) {
@@ -55,13 +41,4 @@ void Gamepad::setButtons(unsigned count, const blink::WebGamepadButton* data)
     }
 }
 
-void Gamepad::trace(Visitor* visitor)
-{
-    visitor->trace(m_buttons);
-}
-
-Gamepad::~Gamepad()
-{
-}
-
 } // namespace WebCore