Make Blacklist::IsBlacklist asynchronous (it will need to be for safe

chrome/browser/extensions/blacklist.h

 // Copyright 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_EXTENSIONS_BLACKLIST_H_
 #define CHROME_BROWSER_EXTENSIONS_BLACKLIST_H_
 
+#include <set>
 #include <string>
 #include <vector>
 
+#include "base/callback.h"
 #include "base/observer_list.h"
 
 namespace extensions {
 
 class Extension;
 class ExtensionPrefs;
 
 // A blacklist of extensions.
 class Blacklist {
  public:
   class Observer {
    public:
     // Observes |blacklist| on construction and unobserves on destruction.
     explicit Observer(Blacklist* blacklist);
 
     virtual void OnBlacklistUpdated() = 0;
 
    protected:
     virtual ~Observer();
 
    private:
     Blacklist* blacklist_;
   };
 
+  typedef base::Callback<void(const std::set<std::string>&)>
+      GetBlacklistedIDsCallback;
+
   // |prefs_| must outlive this.
   explicit Blacklist(ExtensionPrefs* prefs);
 
   ~Blacklist();
 
-  // Gets whether an extension is blacklisted.
-  //
-  // Note that this doesn't entirely determine whether an extension is allowed
-  // to be loaded; there are other considerations (e.g. admin settings).
-  // See extensions::ManagementPolicy (in particular UserMayLoad).
-  bool IsBlacklisted(const std::string& extension_id) const;
-  bool IsBlacklisted(const Extension* extension) const;
+  // From the set of extension IDs passed in via |ids|, asynchronously checks
+  // which are blacklisted and includes them in the resulting set passed
+  // via |callback|, which will be sent on the caller's message loop.
+  void GetBlacklistedIDs(const std::set<std::string>& ids,
+                         const GetBlacklistedIDsCallback& callback);
 
   // Sets the blacklist from the updater to contain the extension IDs in |ids|
   void SetFromUpdater(const std::vector<std::string>& ids,
                       const std::string& version);
 
   // Adds/removes an observer to the blacklist.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
 
  private:
   ObserverList<Observer> observers_;
 
   ExtensionPrefs* const prefs_;
 
+  std::set<std::string> prefs_blacklist_;
+
   DISALLOW_COPY_AND_ASSIGN(Blacklist);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_BLACKLIST_H_