Factor out GamepadCommon base class from Gamepad and WebKitGamepad

Source/modules/gamepad/WebKitGamepad.cpp

Index: Source/modules/gamepad/WebKitGamepad.cpp
diff --git a/Source/modules/gamepad/WebKitGamepad.cpp b/Source/modules/gamepad/WebKitGamepad.cpp
index 5a3fce54e2d5c83cb173ecc6c23bee0a3eee81c5..c83e6604e381a64258ecc494e3abf8e6fb067f84 100644
--- a/Source/modules/gamepad/WebKitGamepad.cpp
+++ b/Source/modules/gamepad/WebKitGamepad.cpp
@@ -8,17 +8,12 @@
 namespace WebCore {
 
 WebKitGamepad::WebKitGamepad()
-    : m_index(0)
-    , m_timestamp(0)
 {
     ScriptWrappable::init(this);
 }
 
-void WebKitGamepad::setAxes(unsigned count, const float* data)
+WebKitGamepad::~WebKitGamepad()
 {
-    m_axes.resize(count);
-    if (count)
-        std::copy(data, data + count, m_axes.begin());
 }
 
 void WebKitGamepad::setButtons(unsigned count, const blink::WebGamepadButton* data)
@@ -28,12 +23,4 @@ void WebKitGamepad::setButtons(unsigned count, const blink::WebGamepadButton* da
         m_buttons[i] = data[i].value;
 }
 
-void WebKitGamepad::trace(Visitor* visitor)
-{
-}
-
-WebKitGamepad::~WebKitGamepad()
-{
-}
-
 } // namespace WebCore