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

chrome/browser/extensions/extension_prefs.h

Index: chrome/browser/extensions/extension_prefs.h
diff --git a/chrome/browser/extensions/extension_prefs.h b/chrome/browser/extensions/extension_prefs.h
index 6adb0156cec8b96cd1721b315c662e1b5aa34534..43a900996ad9503cf69835650c5cf31ad69af262 100644
--- a/chrome/browser/extensions/extension_prefs.h
+++ b/chrome/browser/extensions/extension_prefs.h
@@ -175,6 +175,13 @@ class ExtensionPrefs : public ContentSettingsStore::Observer,
                            Extension::DisableReason disable_reason);
   void ClearDisableReasons(const std::string& extension_id);
 
+  // Gets the set of extensions that have been blacklisted in prefs.
+  std::set<std::string> GetBlacklistedExtensions();
+
+  // Sets whether the extension with |id| is blacklisted.
+  void SetExtensionBlacklisted(const std::string& extension_id,
+                               bool is_blacklisted);
+
   // Returns the version string for the currently installed extension, or
   // the empty string if not found.
   std::string GetVersionString(const std::string& extension_id);
@@ -189,11 +196,11 @@ class ExtensionPrefs : public ContentSettingsStore::Observer,
   // Returns base extensions install directory.
   const FilePath& install_directory() const { return install_directory_; }
 
-  // Updates the prefs based on the blacklist.
-  void UpdateBlacklist(const std::set<std::string>& blacklist_set);
-
-  // Returns whether the extension with |id| is blacklisted.
-  // You probably don't want to call this method, see Blacklist::IsBlacklisted.
+  // Returns whether the extension with |id| has its blacklist bit set.
+  //
+  // WARNING: this only checks the extension's entry in prefs! There may be
+  // other reasons why an extension is blacklisted! You probably want to use
+  // Blacklist::IsBlacklisted rather than this method.
   bool IsExtensionBlacklisted(const std::string& id) const;
 
   // Based on extension id, checks prefs to see if it is orphaned.
@@ -495,7 +502,8 @@ class ExtensionPrefs : public ContentSettingsStore::Observer,
   URLPatternSet GetAllowedInstallSites();
 
  private:
-  friend class ExtensionPrefsUninstallExtension;  // Unit test.
+  friend class ExtensionPrefsBlacklistedExtensions;  // Unit test.
+  friend class ExtensionPrefsUninstallExtension;     // Unit test.
 
   // See the Create methods.
   ExtensionPrefs(PrefService* prefs,