Preventing our default handlers for ChromeOS to show up or confuse the user

chrome/browser/custom_handlers/protocol_handler_registry.h

 // Copyright (c) 2011 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_CUSTOM_HANDLERS_PROTOCOL_HANDLER_REGISTRY_H_
 #define CHROME_BROWSER_CUSTOM_HANDLERS_PROTOCOL_HANDLER_REGISTRY_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 176 matching lines @@
   void Finalize();
 
   // Registers the preferences that we store registered protocol handlers in.
   static void RegisterPrefs(PrefService* prefService);
 
   bool enabled() const { return enabled_; }
 
  private:
   friend class base::RefCountedThreadSafe<ProtocolHandlerRegistry>;
 
+  // Install the default handlers.
+  void InstallFixedHandlers();
+
   // Puts the given handler at the top of the list of handlers for its
   // protocol.
   void PromoteHandler(const ProtocolHandler& handler);
 
   // Clears the default for the provided protocol.
   // Should be called only from the IO thread.
   void ClearDefaultIO(const std::string& scheme);
 
   // Makes this ProtocolHandler the default handler for its protocol.
   // Should be called only from the IO thread.
@@ skipping 63 matching lines @@
   // If false then registered protocol handlers will not be used to handle
   // requests.
   bool enabled_;
 
   // Copy of enabled_ that is only accessed on the IO thread.
   bool enabled_io_;
 
   // Whether or not we are loading.
   bool is_loading_;
 
+  // Once predefined defaults are set, this will be set and an overwrite of
+  // them won't be possible anymore.
+  bool fixed_handlers_loaded_;
+
   DefaultClientObserverList default_client_observers_;
 
   // Copy of default_handlers_ that is only accessed on the IO thread.
   ProtocolHandlerMap default_handlers_io_;
 
   friend class ProtocolHandlerRegistryTest;
   friend class RegisterProtocolHandlerBrowserTest;
 
   DISALLOW_COPY_AND_ASSIGN(ProtocolHandlerRegistry);
 };
 #endif  // CHROME_BROWSER_CUSTOM_HANDLERS_PROTOCOL_HANDLER_REGISTRY_H_