Use a new Supplement constructor for (Worker)Navigator supplements

third_party/WebKit/Source/modules/gamepad/NavigatorGamepad.cpp

Index: third_party/WebKit/Source/modules/gamepad/NavigatorGamepad.cpp
diff --git a/third_party/WebKit/Source/modules/gamepad/NavigatorGamepad.cpp b/third_party/WebKit/Source/modules/gamepad/NavigatorGamepad.cpp
index e148ac8cd68c293cec89db3a426e439f5b04f3f3..81aa202deefbf59d049b085d8eca65251d3d52ef 100644
--- a/third_party/WebKit/Source/modules/gamepad/NavigatorGamepad.cpp
+++ b/third_party/WebKit/Source/modules/gamepad/NavigatorGamepad.cpp
@@ -82,7 +82,7 @@ NavigatorGamepad& NavigatorGamepad::from(Navigator& navigator) {
   NavigatorGamepad* supplement = static_cast<NavigatorGamepad*>(
       Supplement<Navigator>::from(navigator, supplementName()));
   if (!supplement) {
-    supplement = new NavigatorGamepad(navigator.frame());
+    supplement = new NavigatorGamepad(navigator);
     provideTo(navigator, supplementName(), supplement);
   }
   return *supplement;
@@ -166,14 +166,16 @@ void NavigatorGamepad::dispatchOneEvent() {
     m_dispatchOneEventRunner->runAsync();
 }
 
-NavigatorGamepad::NavigatorGamepad(LocalFrame* frame)
-    : ContextLifecycleObserver(frame->document()),
-      PlatformEventController(frame ? frame->page() : 0),
+NavigatorGamepad::NavigatorGamepad(Navigator& navigator)
+    : Supplement<Navigator>(navigator),
+      ContextLifecycleObserver(navigator.frame()->document()),

[sof, 2017/01/23 08:05:31]

ftr, crbug.com/683520 suggests that there's a missing null check on
navigator.frame() in this area. 

(The unconditional use of navigator.frame() is in conflict with the conditional
use on the line below.)

+      PlatformEventController(navigator.frame() ? navigator.frame()->page()
+                                                : 0),
       m_dispatchOneEventRunner(AsyncMethodRunner<NavigatorGamepad>::create(
           this,
           &NavigatorGamepad::dispatchOneEvent)) {
-  if (frame)
-    frame->domWindow()->registerEventListenerObserver(this);
+  if (navigator.frame())
+    navigator.frame()->domWindow()->registerEventListenerObserver(this);
 }
 
 NavigatorGamepad::~NavigatorGamepad() {}