Bug 1895208 - Refactor IsFocusable checks to take flags rather than bool arguments. r=smaug

This doesn't change behavior on its own, but it's likely we want to make
the tab focusability more complicated in bug 1895184, and this will make
changes to this area less painful.

Differential Revision: https://phabricator.services.mozilla.com/D209525

dom/html/HTMLTextAreaElement.cpp

@@ -133,10 +133,11 @@ HTMLTextAreaElement::SelectAll(nsPresContext* aPresContext) {
   return NS_OK;
 }
 
-bool HTMLTextAreaElement::IsHTMLFocusable(bool aWithMouse, bool* aIsFocusable,
+bool HTMLTextAreaElement::IsHTMLFocusable(IsFocusableFlags aFlags,
+                                          bool* aIsFocusable,
                                           int32_t* aTabIndex) {
   if (nsGenericHTMLFormControlElementWithState::IsHTMLFocusable(
-          aWithMouse, aIsFocusable, aTabIndex)) {
+          aFlags, aIsFocusable, aTabIndex)) {
     return true;
   }