Gamepad API: add support for gamepadconnected and gamepaddisconnected events

Source/modules/gamepad/NavigatorGamepad.h

Index: Source/modules/gamepad/NavigatorGamepad.h
diff --git a/Source/modules/gamepad/NavigatorGamepad.h b/Source/modules/gamepad/NavigatorGamepad.h
index 0de60e243802ca9260f0b41096ec7b8a3896e46a..6f9ec626edad1059d838df516ece3da0aeae4880 100644
--- a/Source/modules/gamepad/NavigatorGamepad.h
+++ b/Source/modules/gamepad/NavigatorGamepad.h
@@ -26,6 +26,8 @@
 #ifndef NavigatorGamepad_h
 #define NavigatorGamepad_h
 
+#include "core/frame/DOMWindowLifecycleObserver.h"
+#include "core/frame/DOMWindowProperty.h"
 #include "heap/Handle.h"
 #include "platform/Supplementable.h"
 #include "public/platform/WebGamepads.h"
@@ -36,7 +38,7 @@ class GamepadList;
 class Navigator;
 class WebKitGamepadList;
 
-class NavigatorGamepad FINAL : public Supplement<Navigator> {
+class NavigatorGamepad FINAL : public Supplement<Navigator>, public DOMWindowProperty, public blink::WebGamepadListener, public DOMWindowLifecycleObserver {

[abarth-chromium, 2014/03/17 18:23:46]

You shouldn't need both DOMWindowProperty and DOMWindowLifecycleObserver. 
DOMWindowProperty already gives you all the lifecycle observations you should
need.

[kbalazs, 2014/03/17 23:49:27]

I don't need both indeed. I want to start listening from the time when
addWindowListener is used. This is to not ask the browser process to start the
gamepad code before it is needed because it has a cost (creating the polling
thread). So I kept the inheritance from DOMWindowLifecycleObserver and removed
DOMWindowProperty.

 public:
     virtual ~NavigatorGamepad();
     static NavigatorGamepad& from(Navigator&);
@@ -47,8 +49,13 @@ public:
     WebKitGamepadList* webkitGamepads();
     GamepadList* gamepads();
 
+    virtual void onGamepadConnected(unsigned index, const blink::WebGamepad&) OVERRIDE;
+    virtual void onGamepadDisconnected(unsigned index, const blink::WebGamepad&) OVERRIDE;

[abarth-chromium, 2014/03/17 18:23:46]

We use Obj-C style names:

didConnectGamepad
willDisconnectGamepad

(whichever is appropriate)

[kbalazs, 2014/03/17 23:49:27]

Changed to didConnectGamepad and didDisconnectGamepad.

+
+    virtual void didAddEventListener(DOMWindow*, const AtomicString&) OVERRIDE;
+
 private:
-    NavigatorGamepad();
+    explicit NavigatorGamepad(LocalFrame*);
     static const char* supplementName();
 
     RefPtrWillBePersistent<GamepadList> m_gamepads;