Notify the browser when the page lost interest about gamepads

Source/modules/gamepad/NavigatorGamepad.cpp

Index: Source/modules/gamepad/NavigatorGamepad.cpp
diff --git a/Source/modules/gamepad/NavigatorGamepad.cpp b/Source/modules/gamepad/NavigatorGamepad.cpp
index 0b39cea0a4775edb93e83c9af4196c9516b2f78a..780b1f67be0d20cdf2f55b7c13e42083176b445a 100644
--- a/Source/modules/gamepad/NavigatorGamepad.cpp
+++ b/Source/modules/gamepad/NavigatorGamepad.cpp
@@ -102,6 +102,7 @@ GamepadList* NavigatorGamepad::getGamepads(Navigator& navigator)
 
 WebKitGamepadList* NavigatorGamepad::webkitGamepads()
 {
+    m_wasPolled = true;
     if (!m_webkitGamepads)
         m_webkitGamepads = WebKitGamepadList::create();
     if (window()) {
@@ -113,6 +114,7 @@ WebKitGamepadList* NavigatorGamepad::webkitGamepads()
 
 GamepadList* NavigatorGamepad::gamepads()
 {
+    m_wasPolled = true;
     if (!m_gamepads)
         m_gamepads = GamepadList::create();
     if (window()) {
@@ -160,6 +162,7 @@ NavigatorGamepad::NavigatorGamepad(LocalFrame* frame)
     : DOMWindowProperty(frame)
     , DeviceEventControllerBase(frame ? frame->page() : 0)
     , DOMWindowLifecycleObserver(frame ? frame->domWindow() : 0)
+    , m_wasPolled(false)
 {
 }
 
@@ -228,4 +231,13 @@ void NavigatorGamepad::didRemoveAllEventListeners(LocalDOMWindow*)
     m_hasEventListener = false;
 }
 
+void NavigatorGamepad::pageVisibilityChanged()
+{
+    // Inform the embedder whether it needs to provide gamepad data for us.
+    if (page()->visibilityState() == PageVisibilityStateVisible && (m_hasEventListener || m_wasPolled))
+        startUpdating();
+    else
+        stopUpdating();
+}
+
 } // namespace WebCore