Move renderFallbackContent() into FrameOwner interface.

Source/core/html/HTMLObjectElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Stefan Schimanski (1Stein@gmx.de)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 342 matching lines @@
 void HTMLObjectElement::reattachFallbackContent()
 {
     // This can happen inside of attach() in the middle of a recalcStyle so we need to
     // reattach synchronously here.
     if (document().inStyleRecalc())
         reattach();
     else
         lazyReattachIfAttached();
 }
 
-void HTMLObjectElement::renderFallbackContent()
+bool HTMLObjectElement::renderFallbackContent()
 {
+    if (!inDocument())
+        return false;

[dcheng, 2015/05/06 18:57:38]

I moved this check because if it's not in a document, it doesn't really make
sense to do anything further here.

I could make it return true as well, but logically, I think it makes a little
more sense to return false?

[Nate Chapin, 2015/05/06 20:15:05]

My guess is it's irrelevant. I'd think that any case that's checking the return
value can't happen if inDocument() is false, though I suspect some of the other
callers might need this early exit.

+
     if (useFallbackContent())
-        return;
-
-    if (!inDocument())
-        return;
+        return true;
 
     // Before we give up and use fallback content, check to see if this is a MIME type issue.
     if (m_imageLoader && m_imageLoader->image() && m_imageLoader->image()->status() != Resource::LoadError) {
         m_serviceType = m_imageLoader->image()->response().mimeType();
         if (!isImageType()) {
             // If we don't think we have an image type anymore, then clear the image from the loader.
             m_imageLoader->setImage(0);
             reattachFallbackContent();
-            return;
+            return true;
         }
     }
 
     m_useFallbackContent = true;
 
     // FIXME: Style gets recalculated which is suboptimal.
     reattachFallbackContent();
+    return true;
 }
 
 bool HTMLObjectElement::isExposed() const
 {
     // http://www.whatwg.org/specs/web-apps/current-work/#exposed
     for (HTMLObjectElement* ancestor = Traversal<HTMLObjectElement>::firstAncestor(*this); ancestor; ancestor = Traversal<HTMLObjectElement>::firstAncestor(*ancestor)) {
         if (ancestor->isExposed())
             return false;
     }
     for (HTMLElement& element : Traversal<HTMLElement>::descendantsOf(*this)) {
@@ skipping 54 matching lines @@
 {
     return fastHasAttribute(usemapAttr);
 }
 
 bool HTMLObjectElement::useFallbackContent() const
 {
     return HTMLPlugInElement::useFallbackContent() || m_useFallbackContent;
 }
 
 }