Pass implementation object to supplemental classes by reference

Source/web/WebFrameImpl.cpp

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 736 matching lines @@
         return 0;
     return fromFrame(frame()->tree().child(name));
 }
 
 WebFrame* WebFrameImpl::findChildByExpression(const WebString& xpath) const
 {
     if (xpath.isEmpty())
         return 0;
 
     Document* document = frame()->document();
+    ASSERT(document);
 
-    RefPtrWillBeRawPtr<XPathResult> xpathResult = DocumentXPathEvaluator::evaluate(document, xpath, document, 0, XPathResult::ORDERED_NODE_ITERATOR_TYPE, 0, IGNORE_EXCEPTION);
+    RefPtrWillBeRawPtr<XPathResult> xpathResult = DocumentXPathEvaluator::evaluate(*document, xpath, document, 0, XPathResult::ORDERED_NODE_ITERATOR_TYPE, 0, IGNORE_EXCEPTION);
     if (!xpathResult)
         return 0;
 
     Node* node = xpathResult->iterateNext(IGNORE_EXCEPTION);
     if (!node || !node->isFrameOwnerElement())
         return 0;
     return fromFrame(toHTMLFrameOwnerElement(node)->contentFrame());
 }
 
 WebDocument WebFrameImpl::document() const
@@ skipping 1749 matching lines @@
 
         // There is a possibility that the frame being detached was the only
         // pending one. We need to make sure final replies can be sent.
         flushCurrentScopingEffort(m_findRequestIdentifier);
 
         cancelPendingScopingEffort();
     }
 }
 
 } // namespace blink