Move small c/b/extensions classes into extensions namespace no.2

chrome/browser/ui/views/select_file_dialog_extension.cc

Index: chrome/browser/ui/views/select_file_dialog_extension.cc
diff --git a/chrome/browser/ui/views/select_file_dialog_extension.cc b/chrome/browser/ui/views/select_file_dialog_extension.cc
index 3dfa69cb3de0079d6181a187f40dbf718ace7a99..22bbc2e3d02a117eb0e836b357d7cda12220878c 100644
--- a/chrome/browser/ui/views/select_file_dialog_extension.cc
+++ b/chrome/browser/ui/views/select_file_dialog_extension.cc
@@ -277,7 +277,8 @@ void SelectFileDialogExtension::SelectFileImpl(
         g_browser_process->profile_manager()->GetLoadedProfiles();
     for (std::vector<Profile*>::const_iterator i(profiles.begin());
          i < profiles.end(); ++i) {
-      ShellWindowRegistry* registry = ShellWindowRegistry::Get(*i);
+      extensions::ShellWindowRegistry* registry =
+          extensions::ShellWindowRegistry::Get(*i);
       DCHECK(registry);
       ShellWindow* shell_window = registry->GetShellWindowForNativeWindow(
           owner_window);