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

ui/web_dialogs/web_dialog_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 UI_WEB_DIALOGS_WEB_DIALOG_WEB_CONTENTS_DELEGATE_H_
 #define UI_WEB_DIALOGS_WEB_DIALOG_WEB_CONTENTS_DELEGATE_H_
 
 #include "base/compiler_specific.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "ui/web_dialogs/web_dialogs_export.h"
 
 namespace ui {
 
 // This class implements (and mostly ignores) most of
 // content::WebContentsDelegate for use in a Web dialog. Subclasses need only
 // override a few methods instead of the everything from
 // content::WebContentsDelegate; this way, implementations on all platforms
 // behave consistently.
 class WEB_DIALOGS_EXPORT WebDialogWebContentsDelegate
     : public content::WebContentsDelegate {
  public:
   // Handles OpenURLFromTab and AddNewContents for WebDialogWebContentsDelegate.
   class WebContentsHandler {
    public:
     virtual ~WebContentsHandler() {}
     virtual content::WebContents* OpenURLFromTab(
         content::BrowserContext* context,
         content::WebContents* source,
         const content::OpenURLParams& params) = 0;
-    virtual void AddNewContents(content::BrowserContext* context,
+    // Returns false if the new contents was blocked.
+    virtual bool AddNewContents(content::BrowserContext* context,

[jam, 2012/09/05 06:12:15]

the only implementation of this is in chrome_web_contents_handler.cc, which
doesn't need this blocking mechanism. seems unnecessary to add it here?

                                 content::WebContents* source,
                                 content::WebContents* new_contents,
                                 WindowOpenDisposition disposition,
                                 const gfx::Rect& initial_pos,
                                 bool user_gesture) = 0;
   };
 
   // context and handler must be non-NULL.
   // Takes the ownership of handler.
   WebDialogWebContentsDelegate(content::BrowserContext* context,
                                WebContentsHandler* handler);
 
   virtual ~WebDialogWebContentsDelegate();
 
   // The returned browser context is guaranteed to be original if non-NULL.
   content::BrowserContext* browser_context() const {
     return browser_context_;
   }
 
   // Calling this causes all following events sent from the
   // WebContents object to be ignored.  It also makes all following
   // calls to browser_context() return NULL.
   void Detach();
 
   // content::WebContentsDelegate declarations.
   virtual content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) OVERRIDE;
 
-  virtual void AddNewContents(content::WebContents* source,
+  virtual bool AddNewContents(content::WebContents* source,
                               content::WebContents* new_contents,
                               WindowOpenDisposition disposition,
                               const gfx::Rect& initial_pos,
                               bool user_gesture) OVERRIDE;
   virtual bool IsPopupOrPanel(
       const content::WebContents* source) const OVERRIDE;
   virtual bool ShouldAddNavigationToHistory(
       const history::HistoryAddPageArgs& add_page_args,
       content::NavigationType navigation_type) OVERRIDE;
 
  private:
   // Weak pointer.  Always an original profile.
   content::BrowserContext* browser_context_;
 
   scoped_ptr<WebContentsHandler> handler_;
 
   DISALLOW_COPY_AND_ASSIGN(WebDialogWebContentsDelegate);
 };
 
 }  // namespace ui
 
 #endif  // UI_WEB_DIALOGS_WEB_DIALOG_WEB_CONTENTS_DELEGATE_H_