Convert the PluginService interface to be an async wrapper around PluginList.

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
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/singleton.h"
 #include "base/synchronization/waitable_event_watcher.h"
 #include "build/build_config.h"
 #include "content/browser/plugin_process_host.h"
 #include "content/browser/ppapi_plugin_process_host.h"
 #include "content/browser/ppapi_broker_process_host.h"
 #include "content/common/content_export.h"
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
 #include "googleurl/src/gurl.h"
 #include "ipc/ipc_channel_handle.h"
-#include "webkit/plugins/webplugininfo.h"
 
 #if defined(OS_WIN)
 #include "base/memory/scoped_ptr.h"
 #include "base/win/registry.h"
 #endif
 
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
 #include "base/files/file_path_watcher.h"
 #endif
 
 struct PepperPluginInfo;
 class PluginDirWatcherDelegate;
 
+namespace base {
+class MessageLoopProxy;
+}
+
 namespace content {
 class ResourceContext;
 class PluginServiceFilter;
 }
 
+namespace webkit {
+namespace npapi {
+class PluginGroup;
+class PluginList;
+}
+}
+
 // This must be created on the main thread but it's only called on the IO/file
-// thread.
+// thread. This is an asynchronous wrapper around the PluginList interface for
+// querying plugin information, and this should instead of that class wherever

[jam, 2011/09/22 21:10:59]

nit: we should make this more forceful, i.e. "This must be used instead of that
class to get the plugin list, otherwise expensive disk operation could happen on
the UI/IO threads."

[Robert Sesek, 2011/09/22 23:26:51]

Done. Happily.

+// possible.
 class CONTENT_EXPORT PluginService
     : public base::WaitableEventWatcher::Delegate,
       public NotificationObserver {
  public:
   struct OverriddenPlugin {
     int render_process_id;
     int render_view_id;
     GURL url;  // If empty, the override applies to all urls in render_view.
     webkit::WebPluginInfo plugin;
   };
 
+  typedef base::Callback<void(const std::vector<webkit::WebPluginInfo>&)>
+      GetPluginsCallback;
+  typedef base::Callback<void(const std::vector<webkit::npapi::PluginGroup>&)>
+      GetPluginGroupsCallback;
+
   // Returns the PluginService singleton.
   static PluginService* GetInstance();
 
   // Starts watching for changes in the list of installed plug-ins.
   void StartWatchingPlugins();
 
   // Gets the browser's UI locale.
   const std::string& GetUILocale();
 
   // Returns the plugin process host corresponding to the plugin process that
@@ skipping 38 matching lines @@
                      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);
 
-  // Returns a list of all plug-ins available to the resource context. Must be
-  // called on the FILE thread.
-  void GetPlugins(const content::ResourceContext& context,
-                  std::vector<webkit::WebPluginInfo>* plugins);
+  // Marks the plugin list as dirty and will cause the plugins to be reloaded
+  // on the next access through GetPlugins() or GetPluginGroups().
+  void RefreshPluginList();
+
+  // Asynchronously loads plugins and then calls back to the provided function

[jam, 2011/09/22 21:10:59]

nit: this doesn't always load the plugins, so how about

Returns the plugin list to the provided function asynchronously, loading the
plugins if necessary.

[Robert Sesek, 2011/09/22 23:26:51]

Done and below.

+  // on the calling MessageLoop on completion.
+  void GetPlugins(const GetPluginsCallback& callback);
+
+  // Gets the list of plugin groups, reloading them from disk if marked as dirty

[jam, 2011/09/22 21:10:59]

nit, we should make this the same comment above. better to be vague and say "if
necessary" since RefreshPluginList is not the only thing that causes loading,
i.e. initial load.

+  // with RefreshPluginList().
+  void GetPluginGroups(const GetPluginGroupsCallback& callback);
 
   // Tells all the renderer processes to throw away their cache of the plugin
   // list, and optionally also reload all the pages with plugins.
   // NOTE: can only be called on the UI thread.
   static void PurgePluginListCache(bool reload_pages);
 
   void set_filter(content::PluginServiceFilter* filter) {
     filter_ = filter;
   }
+  content::PluginServiceFilter* filter() { return filter_; }
 
  private:
   friend struct DefaultSingletonTraits<PluginService>;
 
   // Creates the PluginService object, but doesn't actually build the plugin
   // list yet.  It's generated lazily.
   PluginService();
   virtual ~PluginService();
 
   // base::WaitableEventWatcher::Delegate implementation.
   virtual void OnWaitableEventSignaled(base::WaitableEvent* waitable_event);
 
   // NotificationObserver implementation
   virtual void Observe(int type, const NotificationSource& source,
                        const NotificationDetails& details);
 
   void RegisterPepperPlugins();
 
   PepperPluginInfo* GetRegisteredPpapiPluginInfo(const FilePath& plugin_path);
 
+  // Function that is run on the FILE thread to load the plugins synchronously.
+  void GetPluginsInternal(base::MessageLoopProxy* target_loop,
+                          const GetPluginsCallback& callback);
+
   // Helper so we can do the plugin lookup on the FILE thread.
   void GetAllowedPluginForOpenChannelToPlugin(
       int render_process_id,
       int render_view_id,
       const GURL& url,
       const GURL& page_url,
       const std::string& mime_type,
       PluginProcessHost::Client* client,
       const content::ResourceContext* resource_context);
 
@@ skipping 37 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_