Replace the GURL referrer field of OpenURLParams with a content::Referrer

content/browser/tab_contents/tab_contents_observer.h

Index: content/browser/tab_contents/tab_contents_observer.h
diff --git a/content/browser/tab_contents/tab_contents_observer.h b/content/browser/tab_contents/tab_contents_observer.h
index 9b9075816365a96e06228ef4c872ffa8f6d7abe3..b774b6ae10ee8774be45cc29a96a17b3b74e617c 100644
--- a/content/browser/tab_contents/tab_contents_observer.h
+++ b/content/browser/tab_contents/tab_contents_observer.h
@@ -16,6 +16,7 @@ class RenderViewHost;
 
 namespace content {
 struct FrameNavigateParams;
+struct Referrer;
 }
 
 // An observer API implemented by classes which are interested in various page
@@ -75,13 +76,13 @@ class CONTENT_EXPORT TabContentsObserver : public IPC::Channel::Listener,
   virtual void StopNavigation();
 
   virtual void DidOpenURL(const GURL& url,
-                          const GURL& referrer,
+                          const content::Referrer& referrer,
                           WindowOpenDisposition disposition,
                           content::PageTransition transition);
 
   virtual void DidOpenRequestedURL(TabContents* new_contents,
                                    const GURL& url,
-                                   const GURL& referrer,
+                                   const content::Referrer& referrer,
                                    WindowOpenDisposition disposition,
                                    content::PageTransition transition,
                                    int64 source_frame_id);