Remove Windows Metro/WinRT code.

widget/windows/WinMouseScrollHandler.cpp

@@ -326,7 +326,6 @@ bool
 MouseScrollHandler::DispatchEvent(nsWindowBase* aWidget,
                                   WidgetGUIEvent& aEvent)
 {
-  // note, in metrofx, this will always return false for now
   return aWidget->DispatchScrollEvent(&aEvent);
 }
 
@@ -1095,11 +1094,6 @@ MouseScrollHandler::Device::GetWorkaroundPref(const char* aPrefName,
 void
 MouseScrollHandler::Device::Init()
 {
-  // Not supported in metro mode.
-  if (XRE_GetWindowsEnvironment() == WindowsEnvironmentType_Metro) {
-    return;
-  }
-
   sFakeScrollableWindowNeeded =
     GetWorkaroundPref("ui.trackpoint_hack.enabled",
                       (TrackPoint::IsDriverInstalled() ||