Add a chrome://interstitials page.

chrome/browser/safe_browsing/safe_browsing_blocking_page.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.
 //
 // Classes for managing the SafeBrowsing interstitial pages.
 //
 // When a user is about to visit a page the SafeBrowsing system has deemed to
 // be malicious, either as malware or a phishing page, we show an interstitial
 // page with some options (go back, continue) to give the user a chance to avoid
 // the harmful page.
@@ skipping 43 matching lines @@
 }
 
 class SafeBrowsingBlockingPage : public content::InterstitialPageDelegate {
  public:
   typedef SafeBrowsingUIManager::UnsafeResource UnsafeResource;
   typedef std::vector<UnsafeResource> UnsafeResourceList;
   typedef std::map<content::WebContents*, UnsafeResourceList> UnsafeResourceMap;
 
   virtual ~SafeBrowsingBlockingPage();
 
+  // Creates a blocking page. Use ShowBlockingPage if you don't need to access
+  // the blocking page directly.
+  static SafeBrowsingBlockingPage* CreateBlockingPage(
+      SafeBrowsingUIManager* ui_manager,
+      content::WebContents* web_contents,
+      const UnsafeResource& unsafe_resource);
+
   // Shows a blocking page warning the user about phishing/malware for a
   // specific resource.
   // You can call this method several times, if an interstitial is already
   // showing, the new one will be queued and displayed if the user decides
   // to proceed on the currently showing interstitial.
   static void ShowBlockingPage(
       SafeBrowsingUIManager* ui_manager, const UnsafeResource& resource);
 
   // Makes the passed |factory| the factory used to instanciate
   // SafeBrowsingBlockingPage objects. Useful for tests.
@@ skipping 234 matching lines @@
  public:
   virtual ~SafeBrowsingBlockingPageFactory() { }
 
   virtual SafeBrowsingBlockingPage* CreateSafeBrowsingPage(
       SafeBrowsingUIManager* ui_manager,
       content::WebContents* web_contents,
       const SafeBrowsingBlockingPage::UnsafeResourceList& unsafe_resources) = 0;
 };
 
 #endif  // CHROME_BROWSER_SAFE_BROWSING_SAFE_BROWSING_BLOCKING_PAGE_H_