Add PolicyProvider to ExtensionManagement

extensions/browser/extension_prefs.h

Index: extensions/browser/extension_prefs.h
diff --git a/extensions/browser/extension_prefs.h b/extensions/browser/extension_prefs.h
index fcb6882318fc71d5433f091f95b208742eb580fa..4b95e556939f90fe12ec699933971c66b0d8df23 100644
--- a/extensions/browser/extension_prefs.h
+++ b/extensions/browser/extension_prefs.h
@@ -347,11 +347,6 @@ class ExtensionPrefs : public ExtensionScopedPrefs, public KeyedService {
   // reset it. Don't call it unless you mean it!
   bool SetAlertSystemFirstRun();
 
-  // Checks if extensions are blacklisted by default, by policy.
-  // The ManagementPolicy::Provider methods also take this into account, and
-  // should be used instead when the extension ID is known.
-  bool ExtensionsBlacklistedByDefault() const;
-
   // Returns the last value set via SetLastPingDay. If there isn't such a
   // pref, the returned Time will return true for is_null().
   base::Time LastPingDay(const std::string& extension_id) const;