Plumb the referrer throughout the OpenURL APIs....

chrome/browser/views/tabs/dragged_tab_controller.cc

Index: chrome/browser/views/tabs/dragged_tab_controller.cc
===================================================================
--- chrome/browser/views/tabs/dragged_tab_controller.cc	(revision 3991)
+++ chrome/browser/views/tabs/dragged_tab_controller.cc	(working copy)
@@ -143,13 +143,15 @@
 
 void DraggedTabController::OpenURLFromTab(TabContents* source,
                                           const GURL& url,
+                                          const GURL& referrer,
                                           WindowOpenDisposition disposition,
                                           PageTransition::Type transition) {
   if (original_delegate_) {
     if (disposition == CURRENT_TAB)
       disposition = NEW_WINDOW;
 
-    original_delegate_->OpenURLFromTab(source, url, disposition, transition);
+    original_delegate_->OpenURLFromTab(source, url, referrer,
+                                       disposition, transition);
   }
 }