Sanity tweaks to the extension blacklist: check all extensions at once on

chrome/browser/extensions/blacklist.h

Index: chrome/browser/extensions/blacklist.h
diff --git a/chrome/browser/extensions/blacklist.h b/chrome/browser/extensions/blacklist.h
index d5cdce58b8b0c8b5369cf8b4da20a0d7b9569c39..3d6dd8bebc44943bfa324c9ace92188db6cd8272 100644
--- a/chrome/browser/extensions/blacklist.h
+++ b/chrome/browser/extensions/blacklist.h
@@ -55,6 +55,8 @@ class Blacklist : public content::NotificationObserver,
   typedef base::Callback<void(const std::set<std::string>&)>
       GetBlacklistedIDsCallback;
 
+  typedef base::Callback<void(bool)> IsBlacklistedCallback;
+
   // |prefs_| must outlive this.
   explicit Blacklist(ExtensionPrefs* prefs);
 
@@ -69,6 +71,10 @@ class Blacklist : public content::NotificationObserver,
   void GetBlacklistedIDs(const std::set<std::string>& ids,
                          const GetBlacklistedIDsCallback& callback);
 
+  // More convenient form of GetBlacklistedIDs for checking a single extension.
+  void IsBlacklisted(const std::string& extension_id,
+                     const IsBlacklistedCallback& 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);