Never (re)start NavigatorGamepad platform event updating once detached.

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 118aa9453277b573f4789196923a55c8ee597910..c68f061fff5d0497122022d45368e78d7ee3adae 100644
--- a/Source/modules/gamepad/NavigatorGamepad.cpp
+++ b/Source/modules/gamepad/NavigatorGamepad.cpp
@@ -97,11 +97,8 @@ GamepadList* NavigatorGamepad::gamepads()
 {
     if (!m_gamepads)
         m_gamepads = GamepadList::create();
-    if (frame() && frame()->host()) {
-        // The frame must be attached to start updating.
-        startUpdating();
+    if (startUpdatingIfAttached())
         sampleGamepads<Gamepad>(m_gamepads.get());
-    }
     return m_gamepads.get();
 }
 
@@ -115,6 +112,16 @@ void NavigatorGamepad::trace(Visitor* visitor)
     DOMWindowLifecycleObserver::trace(visitor);
 }
 
+bool NavigatorGamepad::startUpdatingIfAttached()
+{
+    // The frame must be attached to start updating.
+    if (frame() && frame()->host()) {
+        startUpdating();
+        return true;
+    }
+    return false;
+}
+
 void NavigatorGamepad::didUpdateData()
 {
     // We should stop listening once we detached.
@@ -214,7 +221,7 @@ void NavigatorGamepad::didAddEventListener(LocalDOMWindow*, const AtomicString&
 {
     if (isGamepadEvent(eventType)) {
         if (page() && page()->visibilityState() == PageVisibilityStateVisible)
-            startUpdating();
+            startUpdatingIfAttached();
         m_hasEventListener = true;
     }
 }
@@ -245,7 +252,7 @@ void NavigatorGamepad::pageVisibilityChanged()
     // Inform the embedder whether it needs to provide gamepad data for us.
     bool visible = page()->visibilityState() == PageVisibilityStateVisible;
     if (visible && (m_hasEventListener || m_gamepads))
-        startUpdating();
+        startUpdatingIfAttached();
     else
         stopUpdating();