Use a placeholder instead of the default plugin for missing plug-ins on Mac and Linux.

content/browser/plugin_service.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.
 
 // This class responds to requests from renderers for the list of plugins, and
 // also a proxy object for plugin instances.
 
 #ifndef CONTENT_BROWSER_PLUGIN_SERVICE_H_
 #define CONTENT_BROWSER_PLUGIN_SERVICE_H_
 #pragma once
@@ skipping 102 matching lines @@
                                 PluginProcessHost::Client* client);
   void OpenChannelToPpapiPlugin(const FilePath& path,
                                 PpapiPluginProcessHost::PluginClient* client);
   void OpenChannelToPpapiBroker(const FilePath& path,
                                 PpapiPluginProcessHost::BrokerClient* client);
 
   // Cancels opening a channel to a NPAPI plugin.
   void CancelOpenChannelToNpapiPlugin(PluginProcessHost::Client* client);
 
   // Gets the plugin in the list of plugins that matches the given url and mime
-  // type. Must be called on the FILE thread if |use_stale| is NULL.
+  // type. Returns true if the data is frome a stale plugin list, false if it
+  // is up to date. This can be called from any thread.
+  bool GetPluginInfoArray(const GURL& url,
+                          const std::string& mime_type,
+                          bool allow_wildcard,
+                          std::vector<webkit::WebPluginInfo>* info,
+                          std::vector<std::string>* actual_mime_types);
+
+  // Gets plugin info for an individual plugin and filters the plugins using
+  // the |context| and renderer IDs. This will report whether the data is stale
+  // via |is_stale| and returns whether or not the plugin can be found.
   bool GetPluginInfo(int render_process_id,
                      int render_view_id,
                      const content::ResourceContext& context,
                      const GURL& url,
                      const GURL& page_url,
                      const std::string& mime_type,
                      bool allow_wildcard,
                      bool* use_stale,
                      webkit::WebPluginInfo* info,
                      std::string* actual_mime_type);
@@ skipping 93 matching lines @@
   content::PluginServiceFilter* filter_;
 
   std::set<PluginProcessHost::Client*> pending_plugin_clients_;
 
   DISALLOW_COPY_AND_ASSIGN(PluginService);
 };
 
 DISABLE_RUNNABLE_METHOD_REFCOUNT(PluginService);
 
 #endif  // CONTENT_BROWSER_PLUGIN_SERVICE_H_