IDL: make optional arguments (without default) explicit sometimes

Source/core/css/FontFaceSet.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 339 matching lines @@
     Document* d = document();
     d->ensureStyleResolver(); // Flush pending style changes.
     return d->styleEngine()->fontSelector()->fontFaceCache()->cssConnectedFontFaces();
 }
 
 bool FontFaceSet::isCSSConnectedFontFace(FontFace* fontFace) const
 {
     return cssConnectedFontFaceList().contains(fontFace);
 }
 
-void FontFaceSet::forEach(PassOwnPtr<FontFaceSetForEachCallback> callback, ScriptValue& thisArg) const
-{
-    forEachInternal(callback, &thisArg);
-}
-
-void FontFaceSet::forEach(PassOwnPtr<FontFaceSetForEachCallback> callback) const
-{
-    forEachInternal(callback, 0);
-}
-
-void FontFaceSet::forEachInternal(PassOwnPtr<FontFaceSetForEachCallback> callback, ScriptValue* thisArg) const
+void FontFaceSet::forEach(PassOwnPtr<FontFaceSetForEachCallback> callback, const Optional<ScriptValue>& thisArg) const
 {
     if (!inActiveDocumentContext())
         return;
     const WillBeHeapListHashSet<RefPtrWillBeMember<FontFace> >& cssConnectedFaces = cssConnectedFontFaceList();
     WillBeHeapVector<RefPtrWillBeMember<FontFace> > fontFaces;
     fontFaces.reserveInitialCapacity(cssConnectedFaces.size() + m_nonCSSConnectedFaces.size());
     for (WillBeHeapListHashSet<RefPtrWillBeMember<FontFace> >::const_iterator it = cssConnectedFaces.begin(); it != cssConnectedFaces.end(); ++it)
         fontFaces.append(*it);
     for (WillBeHeapListHashSet<RefPtrWillBeMember<FontFace> >::const_iterator it = m_nonCSSConnectedFaces.begin(); it != m_nonCSSConnectedFaces.end(); ++it)
         fontFaces.append(*it);
 
     for (size_t i = 0; i < fontFaces.size(); ++i) {
         FontFace* face = fontFaces[i].get();
-        if (thisArg)
-            callback->handleItem(*thisArg, face, face, const_cast<FontFaceSet*>(this));
+        if (thisArg.isMissing())
+            callback->handleItem(face, face, const_cast<FontFaceSet*>(this));
         else
-            callback->handleItem(face, face, const_cast<FontFaceSet*>(this));
+            callback->handleItem(thisArg.get(), face, face, const_cast<FontFaceSet*>(this));
     }
 }
 
 unsigned long FontFaceSet::size() const
 {
     if (!inActiveDocumentContext())
         return m_nonCSSConnectedFaces.size();
     return cssConnectedFontFaceList().size() + m_nonCSSConnectedFaces.size();
 }
 
@@ skipping 195 matching lines @@
     visitor->trace(m_loadingFonts);
     visitor->trace(m_loadedFonts);
     visitor->trace(m_failedFonts);
     visitor->trace(m_nonCSSConnectedFaces);
     DocumentSupplement::trace(visitor);
     EventTargetWithInlineData::trace(visitor);
 }
 #endif
 
 } // namespace blink