Block navigations in extensions via ShouldTransferNavigation (not via OpenURL).

content/public/browser/web_contents_delegate.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_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_DELEGATE_H_
 
 #include <stdint.h>
 
 #include <set>
@@ skipping 80 matching lines @@
   // OpenURL() for these cases which does it for you).
 
   // Returns the WebContents the URL is opened in, or nullptr if the URL wasn't
   // opened immediately.
   virtual WebContents* OpenURLFromTab(WebContents* source,
                                       const OpenURLParams& params);
 
   // Allows the delegate to optionally cancel navigations that attempt to
   // transfer to a different process between the start of the network load and
   // commit.  Defaults to true.
-  virtual bool ShouldTransferNavigation();
+  virtual bool ShouldTransferNavigation(bool is_main_frame_navigation);
 
   // Called to inform the delegate that the WebContents's navigation state
   // changed. The |changed_flags| indicates the parts of the navigation state
   // that have been updated.
   virtual void NavigationStateChanged(WebContents* source,
                                       InvalidateTypes changed_flags) {}
 
   // Called to inform the delegate that the WebContent's visible SSL state (as
   // defined by SSLStatus) changed.
   virtual void VisibleSSLStateChanged(const WebContents* source) {}
@@ skipping 432 matching lines @@
   // Called when |this| is no longer the WebContentsDelegate for |source|.
   void Detach(WebContents* source);
 
   // The WebContents that this is currently a delegate for.
   std::set<WebContents*> attached_contents_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_DELEGATE_H_