Support for interactive set-chrome-as-default in Windows.

chrome/browser/custom_handlers/protocol_handler_registry.cc

 // Copyright (c) 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.
 
 #include "chrome/browser/custom_handlers/protocol_handler_registry.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 21 matching lines @@
 // If true default protocol handlers will be removed if the OS level
 // registration for a protocol is no longer Chrome.
 bool ShouldRemoveHandlersNotInOS() {
 #if defined(OS_LINUX)
   // We don't do this on Linux as the OS registration there is not reliable,
   // and Chrome OS doesn't have any notion of OS registration.
   // TODO(benwells): When Linux support is more reliable remove this
   // difference (http://crbug.com/88255).
   return false;
 #else
-  return ShellIntegration::CanSetAsDefaultProtocolClient();
+  return ShellIntegration::CanSetAsDefaultProtocolClient() !=
+      ShellIntegration::SET_DEFAULT_NOT_ALLOWED;
 #endif
 }
 
 } // namespace
 
 static const ProtocolHandler& LookupHandler(
     const ProtocolHandlerRegistry::ProtocolHandlerMap& handler_map,
     const std::string& scheme) {
   ProtocolHandlerRegistry::ProtocolHandlerMap::const_iterator p =
       handler_map.find(scheme);
@@ skipping 661 matching lines @@
 
 void ProtocolHandlerRegistry::AddPredefinedHandler(
     const ProtocolHandler& handler) {
   // If called after the load command was issued this function will fail.
   DCHECK(!is_loaded_);
   RegisterProtocolHandler(handler);
   SetDefault(handler);
 }