[Extensions] Clean up the handling of ExtensionHostMsg_Request

extensions/browser/guest_view/web_view/web_view_guest_delegate.h

Index: extensions/browser/guest_view/web_view/web_view_guest_delegate.h
diff --git a/extensions/browser/guest_view/web_view/web_view_guest_delegate.h b/extensions/browser/guest_view/web_view/web_view_guest_delegate.h
index cf827bab870d0a426a773a8cc3609efd3a932306..1fbabf8ea33f18fe89917721e906152887bc040e 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest_delegate.h
+++ b/extensions/browser/guest_view/web_view/web_view_guest_delegate.h
@@ -35,9 +35,6 @@ class WebViewGuestDelegate {
   // Called when context menu operation was handled.
   virtual bool HandleContextMenu(const content::ContextMenuParams& params) = 0;
 
-  // Called to attach helpers just after additional initialization is performed.
-  virtual void OnAttachWebViewHelpers(content::WebContents* contents) = 0;
-
   // Called just after additional initialization is performed.
   virtual void OnDidInitialize() = 0;