Watch for filtering pref changes in ManagedModeInterstitial and unblock requests if they become…

chrome/browser/managed_mode/managed_mode_interstitial.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 CHROME_BROWSER_MANAGED_MODE_MANAGED_MODE_INTERSTITIAL_H_
 #define CHROME_BROWSER_MANAGED_MODE_MANAGED_MODE_INTERSTITIAL_H_
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/compiler_specific.h"
-#include "base/memory/weak_ptr.h"
+#include "base/prefs/pref_change_registrar.h"
 #include "content/public/browser/interstitial_page_delegate.h"
 #include "url/gurl.h"
 
 namespace content {
 class InterstitialPage;
 class WebContents;
 }
 
 // Delegate for an interstitial page when a page is blocked in managed mode
 // because it is not on any whitelist. It lets an authorized user preview the
 // blocked page, to decide later whether to manually allow it.
 class ManagedModeInterstitial : public content::InterstitialPageDelegate {
  public:
   ManagedModeInterstitial(content::WebContents* web_contents,
                           const GURL& url,
                           const base::Callback<void(bool)>& callback);
   virtual ~ManagedModeInterstitial();
 
  private:
   // InterstitialPageDelegate implementation.
   virtual std::string GetHTMLContents() OVERRIDE;
   virtual void CommandReceived(const std::string& command) OVERRIDE;
   virtual void OnProceed() OVERRIDE;
   virtual void OnDontProceed() OVERRIDE;
 
+  // Returns whether the blocked URL is now allowed. Called initially before the
+  // interstitial is shown (to catch race conditions), or when the URL filtering
+  // prefs change.
+  bool ShouldProceed();
+
+  void OnFilteringPrefsChanged();
   void DispatchContinueRequest(bool continue_request);
 
   // Owns the interstitial, which owns us.
   content::WebContents* web_contents_;
 
   content::InterstitialPage* interstitial_page_;  // Owns us.
 
+  PrefChangeRegistrar pref_change_registrar_;
+
   // The UI language. Used for formatting the URL for display.
   std::string languages_;
   GURL url_;
 
-  base::WeakPtrFactory<ManagedModeInterstitial> weak_ptr_factory_;
   base::Callback<void(bool)> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(ManagedModeInterstitial);
 };
 
 #endif  // CHROME_BROWSER_MANAGED_MODE_MANAGED_MODE_INTERSTITIAL_H_