Show missing plug-in infobar only if a plug-in is available.

chrome/default_plugin/plugin_impl_mac.mm

 // 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.
 
 #include "chrome/default_plugin/plugin_impl_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/file_util.h"
 #include "base/path_service.h"
@@ skipping 39 matching lines @@
 
   instance_ = instance;
   mime_type_ = mime_type;
 
   command_ = [l10n_util::FixUpWindowsStyleLabel(l10n_util::GetStringUTF16(
       IDS_DEFAULT_PLUGIN_NO_PLUGIN_AVAILABLE_MSG)) retain];
 
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
   image_ = rb.GetNativeImageNamed(IDR_PLUGIN_ICON);
 
-  return PluginInstallerBase::Initialize(module_handle, instance, mime_type,
-                                         argc, argn, argv);
+  PluginInstallerBase::SetRoutingIds(argc, argn, argv);
+  return true;
 }
 
 bool PluginInstallerImpl::NPP_SetWindow(NPWindow* window_info) {
   width_ = window_info->width;
   height_ = window_info->height;
   return true;
 }
 
 void PluginInstallerImpl::Shutdown() {
 }
@@ skipping 123 matching lines @@
 }
 
 void PluginInstallerImpl::NotifyPluginStatus(int status) {
   ChildThread::current()->Send(
       new ChromePluginProcessHostMsg_MissingPluginStatus(
           status,
           renderer_process_id(),
           render_view_id(),
           0));
 }