Have Frame::loader() return a reference

Source/core/html/PluginDocument.cpp

 /*
  * Copyright (C) 2006, 2008 Apple 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 63 matching lines @@
     // FIXME: Assert we have a loader to figure out why the original null checks
     // and assert were added for the security bug in http://trac.webkit.org/changeset/87566
     ASSERT(document());
     RELEASE_ASSERT(document()->loader());
 
     Frame* frame = document()->frame();
     if (!frame)
         return;
 
     // FIXME: Why does this check settings?
-    if (!frame->settings() || !frame->loader()->allowPlugins(NotAboutToInstantiatePlugin))
+    if (!frame->settings() || !frame->loader().allowPlugins(NotAboutToInstantiatePlugin))
         return;
 
     RefPtr<HTMLHtmlElement> rootElement = HTMLHtmlElement::create(*document());
     rootElement->insertedByParser();
     document()->appendChild(rootElement);
-    frame->loader()->dispatchDocumentElementAvailable();
+    frame->loader().dispatchDocumentElementAvailable();
 
     RefPtr<HTMLBodyElement> body = HTMLBodyElement::create(*document());
     body->setAttribute(marginwidthAttr, "0");
     body->setAttribute(marginheightAttr, "0");
     body->setAttribute(styleAttr, "background-color: rgb(38,38,38)");
     rootElement->appendChild(body);
 
     m_embedElement = HTMLEmbedElement::create(*document());
     m_embedElement->setAttribute(widthAttr, "100%");
     m_embedElement->setAttribute(heightAttr, "100%");
@@ skipping 83 matching lines @@
     HTMLDocument::detach(context);
 }
 
 void PluginDocument::cancelManualPluginLoad()
 {
     // PluginDocument::cancelManualPluginLoad should only be called once, but there are issues
     // with how many times we call beforeload on object elements. <rdar://problem/8441094>.
     if (!shouldLoadPluginManually())
         return;
 
-    DocumentLoader* documentLoader = frame()->loader()->activeDocumentLoader();
+    DocumentLoader* documentLoader = frame()->loader().activeDocumentLoader();
     documentLoader->cancelMainResourceLoad(ResourceError::cancelledError(documentLoader->request().url()));
     setShouldLoadPluginManually(false);
 }
 
 }