Remove BrowserPlugin's -internal-attach method

chrome/browser/renderer_host/chrome_extension_message_filter.h

Index: chrome/browser/renderer_host/chrome_extension_message_filter.h
diff --git a/chrome/browser/renderer_host/chrome_extension_message_filter.h b/chrome/browser/renderer_host/chrome_extension_message_filter.h
index 781afea26aad9b5b54f7de45d47aa5b2dca4b9f5..8d2d96718c1de707b99116f2db4775c25cc246f8 100644
--- a/chrome/browser/renderer_host/chrome_extension_message_filter.h
+++ b/chrome/browser/renderer_host/chrome_extension_message_filter.h
@@ -50,6 +50,11 @@ class ChromeExtensionMessageFilter : public content::BrowserMessageFilter,
   void OnCanTriggerClipboardRead(const GURL& origin, bool* allowed);
   void OnCanTriggerClipboardWrite(const GURL& origin, bool* allowed);
 
+  void OnAttachGuest(int routing_id,
+                     int element_instance_id,
+                     int guest_instance_id,
+                     const base::DictionaryValue& attach_params);
+
   // TODO(jamescook): Move these functions into the extensions module. Ideally
   // this would be in extensions::ExtensionMessageFilter but that will require
   // resolving the MessageService and ActivityLog dependencies on src/chrome.