Bug 1405087: Don't use -moz-user-input: disabled to decide event handling stuff. r=smaug

We only set it on disabled form controls anyway, so use the content state
directly.

MozReview-Commit-ID: 7jJ75dvszyC

layout/forms/nsCheckboxRadioFrame.cpp

@@ -185,10 +185,8 @@ nsCheckboxRadioFrame::HandleEvent(nsPresContext* aPresContext,
                                   WidgetGUIEvent* aEvent,
                                   nsEventStatus* aEventStatus)
 {
-  // Check for user-input:none style
-  const nsStyleUserInterface* uiStyle = StyleUserInterface();
-  if (uiStyle->mUserInput == StyleUserInput::None ||
-      uiStyle->mUserInput == StyleUserInput::Disabled) {
+  // Check for disabled content so that selection works properly (?).
+  if (IsContentDisabled()) {
     return nsFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
   }
   return NS_OK;