Pass result of blockage across content API when new tab blocked.

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 <set>
 #include <string>
 
@@ skipping 77 matching lines @@
   virtual void NavigationStateChanged(const WebContents* source,
                                       unsigned changed_flags) {}
 
   // Adds the navigation request headers to |headers|. Use
   // net::HttpUtil::AppendHeaderIfMissing to build the set of headers.
   virtual void AddNavigationHeaders(const GURL& url, std::string* headers) {}
 
   // Creates a new tab with the already-created WebContents 'new_contents'.
   // The window for the added contents should be reparented correctly when this
   // method returns.  If |disposition| is NEW_POPUP, |pos| should hold the
-  // initial position.
-  virtual void AddNewContents(WebContents* source,
+  // initial position. Returns false if the tab is blocked.
+  virtual bool AddNewContents(WebContents* source,
                               WebContents* new_contents,
                               WindowOpenDisposition disposition,
                               const gfx::Rect& initial_pos,
-                              bool user_gesture) {}
+                              bool user_gesture);
 
   // Selects the specified contents, bringing its container to the front.
   virtual void ActivateContents(WebContents* contents) {}
 
   // Deactivates the specified contents by deactivating its container and
   // potentialy moving it to the back of the Z order.
   virtual void DeactivateContents(WebContents* contents) {}
 
   // Notifies the delegate that this contents is starting or is done loading
   // some resource. The delegate should use this notification to represent
@@ skipping 326 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_