Use a resource throttle to implement shouldOverrideUrlLoading.

content/public/browser/web_contents_observer.h

 // Copyright (c) 2012 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_WEB_CONTENTS_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 
 #include "base/process/kill.h"
 #include "base/process/process_handle.h"
 #include "content/common/content_export.h"
@@ skipping 143 matching lines @@
   virtual void DidCommitProvisionalLoadForFrame(
       RenderFrameHost* render_frame_host,
       const GURL& url,
       ui::PageTransition transition_type) {}
 
   // This method is invoked when the provisional load failed.
   virtual void DidFailProvisionalLoad(
       RenderFrameHost* render_frame_host,
       const GURL& validated_url,
       int error_code,
-      const base::string16& error_description) {}
+      const base::string16& error_description,
+      bool was_ignored_by_handler) {}
 
   // If the provisional load corresponded to the main frame, this method is
   // invoked in addition to DidCommitProvisionalLoadForFrame.
   virtual void DidNavigateMainFrame(
       const LoadCommittedDetails& details,
       const FrameNavigateParams& params) {}
 
   // And regardless of what frame navigated, this method is invoked after
   // DidCommitProvisionalLoadForFrame was invoked.
   virtual void DidNavigateAnyFrame(
@@ skipping 21 matching lines @@
   // pages, DidFinishLoad is invoked for frames that were not sending
   // navigational events before. It is safe to ignore these events.
   virtual void DidFinishLoad(RenderFrameHost* render_frame_host,
                              const GURL& validated_url) {}
 
   // This method is like DidFinishLoad, but when the load failed or was
   // cancelled, e.g. window.stop() is invoked.
   virtual void DidFailLoad(RenderFrameHost* render_frame_host,
                            const GURL& validated_url,
                            int error_code,
-                           const base::string16& error_description) {}
+                           const base::string16& error_description,
+                           bool was_ignored_by_handler) {}
 
   // This method is invoked when content was loaded from an in-memory cache.
   virtual void DidLoadResourceFromMemoryCache(
       const LoadFromMemoryCacheDetails& details) {}
 
   // This method is invoked when a response has been received for a resource
   // request.
   virtual void DidGetResourceResponseStart(
       const ResourceRequestDetails& details) {}
 
@@ skipping 169 matching lines @@
   void ResetWebContents();
 
   WebContentsImpl* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_