Ensure we don't load plugins on the IO thread

chrome/browser/plugin_service.h

 // Copyright (c) 2006-2008 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 CHROME_BROWSER_PLUGIN_SERVICE_H_
 #define CHROME_BROWSER_PLUGIN_SERVICE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/hash_tables.h"
-#include "base/lock.h"
 #include "base/ref_counted.h"
 #include "base/singleton.h"
 #include "base/waitable_event_watcher.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/glue/webplugininfo.h"
 
 #if defined(OS_WIN)
 #include "base/registry.h"
 #endif
 
 namespace IPC {
 class Message;
 }
 
 class MessageLoop;
 class PluginProcessHost;
 class URLRequestContext;
 class ResourceDispatcherHost;
 class ResourceMessageFilter;
 
-// This can be called on the main thread and IO thread.  However it must
-// be created on the main thread.
+// This must be created on the main thread but it's only called on the IO/file
+// thread.
 class PluginService
     : public base::WaitableEventWatcher::Delegate,
       public NotificationObserver {
  public:
   // Returns the PluginService singleton.
   static PluginService* GetInstance();
 
-  // Gets the list of available plugins.
-  void GetPlugins(bool refresh, std::vector<WebPluginInfo>* plugins);
-
   // Load all the plugins that should be loaded for the lifetime of the browser
   // (ie, with the LoadOnStartup flag set).
   void LoadChromePlugins(ResourceDispatcherHost* resource_dispatcher_host);
 
   // Sets/gets the data directory that Chrome plugins should use to store
   // persistent data.
   void SetChromePluginDataDir(const FilePath& data_dir);
   const FilePath& GetChromePluginDataDir();
 
   // Gets the browser's UI locale.
@@ skipping 14 matching lines @@
   // Opens a channel to a plugin process for the given mime type, starting
   // a new plugin process if necessary.  This must be called on the IO thread
   // or else a deadlock can occur.
   void OpenChannelToPlugin(ResourceMessageFilter* renderer_msg_filter,
                            const GURL& url,
                            const std::string& mime_type,
                            const std::string& clsid,
                            const std::wstring& locale,
                            IPC::Message* reply_msg);
 
-  bool HavePluginFor(const std::string& mime_type, bool allow_wildcard);
-
   // Get the path to the plugin specified.  policy_url is the URL of the page
   // requesting the plugin, so we can verify whether the plugin is allowed
   // on that page.
   FilePath GetPluginPath(const GURL& url,
                          const GURL& policy_url,
                          const std::string& mime_type,
                          const std::string& clsid,
                          std::string* actual_mime_type);
 
   // The UI thread's message loop
@@ skipping 11 matching lines @@
   PluginService();
   ~PluginService();
 
   // base::WaitableEventWatcher::Delegate implementation.
   virtual void OnWaitableEventSignaled(base::WaitableEvent* waitable_event);
 
   // NotificationObserver implementation
   virtual void Observe(NotificationType type, const NotificationSource& source,
                        const NotificationDetails& details);
 
-  // Get plugin info by matching full path.
-  bool GetPluginInfoByPath(const FilePath& plugin_path, WebPluginInfo* info);
-
   // Returns true if the given plugin is allowed to be used by a page with
   // the given URL.
   bool PluginAllowedForURL(const FilePath& plugin_path, const GURL& url);
 
   // mapping between plugin path and PluginProcessHost
   typedef base::hash_map<FilePath, PluginProcessHost*> PluginMap;
   PluginMap plugin_hosts_;
 
   // The main thread's message loop.
   MessageLoop* main_message_loop_;
 
   // The IO thread's resource dispatcher host.
   ResourceDispatcherHost* resource_dispatcher_host_;
 
   // The data directory that Chrome plugins should use to store persistent data.
   FilePath chrome_plugin_data_dir_;
 
   // The browser's UI locale.
   const std::wstring ui_locale_;
 
   // Map of plugin paths to the origin they are restricted to.  Used for
   // extension-only plugins.
   typedef base::hash_map<FilePath, GURL> PrivatePluginMap;
   PrivatePluginMap private_plugins_;
 
-  // Need synchronization whenever we access the plugin_list singelton through
-  // webkit_glue since this class is called on the main and IO thread.
-  Lock lock_;
-
   NotificationRegistrar registrar_;
 
 #if defined(OS_WIN)
   // Registry keys for getting notifications when new plugins are installed.
   RegKey hkcu_key_;
   RegKey hklm_key_;
   scoped_ptr<base::WaitableEvent> hkcu_event_;
   scoped_ptr<base::WaitableEvent> hklm_event_;
   base::WaitableEventWatcher hkcu_watcher_;
   base::WaitableEventWatcher hklm_watcher_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(PluginService);
 };
 
 #endif  // CHROME_BROWSER_PLUGIN_SERVICE_H_