IDL: make optional arguments (without default) explicit sometimes

Source/core/dom/DOMTokenList.cpp

Index: Source/core/dom/DOMTokenList.cpp
diff --git a/Source/core/dom/DOMTokenList.cpp b/Source/core/dom/DOMTokenList.cpp
index b434de742135c97e057c103ca3a1c70f0ba875c1..3f2482cf4a3b8ae742b8cd5f9d67ce95482de83e 100644
--- a/Source/core/dom/DOMTokenList.cpp
+++ b/Source/core/dom/DOMTokenList.cpp
@@ -121,30 +121,23 @@ void DOMTokenList::remove(const Vector<String>& tokens, ExceptionState& exceptio
         setValue(removeTokens(value(), tokens));
 }
 
-bool DOMTokenList::toggle(const AtomicString& token, ExceptionState& exceptionState)
+bool DOMTokenList::toggle(const AtomicString& token, Optional<bool> force, ExceptionState& exceptionState)
 {
     if (!validateToken(token, exceptionState))
         return false;
 
     if (containsInternal(token)) {
-        removeInternal(token);
-        return false;
-    }
-    addInternal(token);
-    return true;
-}
-
-bool DOMTokenList::toggle(const AtomicString& token, bool force, ExceptionState& exceptionState)
-{
-    if (!validateToken(token, exceptionState))
-        return false;
-
-    if (force)
+        if (force.isMissing() || !force.get()) {
+            removeInternal(token);
+            return false;
+        }
+        return true;
+    } else {
+        if (!force.isMissing() && !force.get())
+            return false;
         addInternal(token);
-    else
-        removeInternal(token);
-
-    return force;
+        return true;
+    }
 }
 
 void DOMTokenList::addInternal(const AtomicString& token)