Fixing iframe jank in the local omnibox popup.

content/public/browser/url_data_source.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_
 #define CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 88 matching lines @@
   // By default, the "X-Frame-Options: DENY" header is sent. To stop this from
   // happening, return false. It is OK to return false as needed.
   virtual bool ShouldDenyXFrameOptions() const;
 
   // By default, only chrome: and chrome-devtools: requests are allowed.
   // Override in specific WebUI data sources to enable for additional schemes or
   // to implement fancier access control.  Typically used in concert with
   // ContentBrowserClient::GetAdditionalWebUISchemes() to permit additional
   // WebUI scheme support for an embedder.
   virtual bool ShouldServiceRequest(const net::URLRequest* request) const;
+
+  // Called to inform the source that StartDataRequest() will be called soon.
+  // Gives the source an opportunity to rewrite |path| to incorporate extra
+  // information from the URLRequest prior to serving.
+  virtual void WillServiceRequest(
+      const net::URLRequest* request,
+      std::string* path) const {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_URL_DATA_SOURCE_H_