Use PostTaskAndReplyWithResult in plugin_service_impl.cc.

content/public/browser/plugin_service.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_PLUGIN_SERVICE_H_
 #define CONTENT_PUBLIC_BROWSER_PLUGIN_SERVICE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 19 matching lines @@
 class ResourceContext;
 struct PepperPluginInfo;
 struct WebPluginInfo;
 
 // This must be created on the main thread but it's only called on the IO/file
 // thread. This is an asynchronous wrapper around the PluginList interface for
 // querying plugin information. This must be used instead of that to avoid
 // doing expensive disk operations on the IO/UI threads.
 class PluginService {
  public:
-  typedef base::Callback<void(const std::vector<WebPluginInfo>&)>
-      GetPluginsCallback;
+  using GetPluginsCallback =
+      base::OnceCallback<void(const std::vector<WebPluginInfo>&)>;
 
   // Returns the PluginService singleton.
   CONTENT_EXPORT static PluginService* GetInstance();
 
   // Tells all the renderer processes associated with the given browser context
   // to throw away their cache of the plugin list, and optionally also reload
   // all the pages with plugins. If |browser_context| is nullptr, purges the
   // cache in all renderers.
   // NOTE: can only be called on the UI thread.
   CONTENT_EXPORT static void PurgePluginListCache(
@@ skipping 35 matching lines @@
   virtual bool GetPluginInfoByPath(const base::FilePath& plugin_path,
                                    WebPluginInfo* info) = 0;
 
   // Returns the display name for the plugin identified by the given path. If
   // the path doesn't identify a plugin, or the plugin has no display name,
   // this will attempt to generate a display name from the path.
   virtual base::string16 GetPluginDisplayNameByPath(
       const base::FilePath& plugin_path) = 0;
 
   // Asynchronously loads plugins if necessary and then calls back to the
-  // provided function on the calling MessageLoop on completion.
-  virtual void GetPlugins(const GetPluginsCallback& callback) = 0;
+  // provided function on the calling sequence on completion.
+  virtual void GetPlugins(GetPluginsCallback callback) = 0;
 
   // Returns information about a pepper plugin if it exists, otherwise nullptr.
   // The caller does not own the pointer, and it's not guaranteed to live past
   // the call stack.
   virtual PepperPluginInfo* GetRegisteredPpapiPluginInfo(
       const base::FilePath& plugin_path) = 0;
 
   virtual void SetFilter(PluginServiceFilter* filter) = 0;
   virtual PluginServiceFilter* GetFilter() = 0;
 
@@ skipping 21 matching lines @@
   virtual void GetInternalPlugins(std::vector<WebPluginInfo>* plugins) = 0;
 
   // Returns true iff PPAPI "dev channel" methods are supported.
   virtual bool PpapiDevChannelSupported(BrowserContext* browser_context,
                                         const GURL& document_url) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_PLUGIN_SERVICE_H_