Have Frame::loader() return a reference

Source/core/html/PluginDocument.cpp

Index: Source/core/html/PluginDocument.cpp
diff --git a/Source/core/html/PluginDocument.cpp b/Source/core/html/PluginDocument.cpp
index 04511b514ba01ab909249f587a6fb65593e6ba6f..e36e8d804f7dd329dceb54aa94d0ace1ba339ba5 100644
--- a/Source/core/html/PluginDocument.cpp
+++ b/Source/core/html/PluginDocument.cpp
@@ -81,13 +81,13 @@ void PluginDocumentParser::createDocumentStructure()
         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");
@@ -191,7 +191,7 @@ void PluginDocument::cancelManualPluginLoad()
     if (!shouldLoadPluginManually())
         return;
 
-    DocumentLoader* documentLoader = frame()->loader()->activeDocumentLoader();
+    DocumentLoader* documentLoader = frame()->loader().activeDocumentLoader();
     documentLoader->cancelMainResourceLoad(ResourceError::cancelledError(documentLoader->request().url()));
     setShouldLoadPluginManually(false);
 }