Get rid of the last RenderViewHostDelegate usage in chrome.

chrome/browser/extensions/extension_tabs_module.cc

Index: chrome/browser/extensions/extension_tabs_module.cc
===================================================================
--- chrome/browser/extensions/extension_tabs_module.cc	(revision 138434)
+++ chrome/browser/extensions/extension_tabs_module.cc	(working copy)
@@ -1527,13 +1527,10 @@
       return false;
     }
 
-    // Close the tab in this convoluted way, since there's a chance that the tab
-    // is being dragged, or we're in some other nested event loop. This code
-    // path should ensure that the tab is safely closed under such
-    // circumstances, whereas |Browser::CloseTabContents()| does not.
-    RenderViewHost* render_view_host =
-        contents->web_contents()->GetRenderViewHost();
-    render_view_host->GetDelegate()->Close(render_view_host);
+    // There's a chance that the tab is being dragged, or we're in some other
+    // nested event loop. This code path ensures that the tab is safely closed
+    // under such circumstances, whereas |Browser::CloseTabContents()| does not.
+    contents->web_contents()->Close();
   }
   return true;
 }