Revert "content: Remove use of MessageLoopProxy and deprecated MessageLoop APIs"

content/browser/plugin_service_impl.h

Index: content/browser/plugin_service_impl.h
diff --git a/content/browser/plugin_service_impl.h b/content/browser/plugin_service_impl.h
index 19fefba66415ddb996a0b5a299deea107c6a104d..2e107a6d40a6791d328e9806e713135f6fecd036 100644
--- a/content/browser/plugin_service_impl.h
+++ b/content/browser/plugin_service_impl.h
@@ -42,7 +42,7 @@
 #endif
 
 namespace base {
-class SingleThreadTaskRunner;
+class MessageLoopProxy;
 }
 
 namespace content {
@@ -181,12 +181,13 @@ class CONTENT_EXPORT PluginServiceImpl
   void RegisterPepperPlugins();
 
   // Run on the blocking pool to load the plugins synchronously.
-  void GetPluginsInternal(base::SingleThreadTaskRunner* target_task_runner,
+  void GetPluginsInternal(base::MessageLoopProxy* target_loop,
                           const GetPluginsCallback& callback);
 
 #if defined(OS_POSIX)
-  void GetPluginsOnIOThread(base::SingleThreadTaskRunner* target_task_runner,
-                            const GetPluginsCallback& callback);
+  void GetPluginsOnIOThread(
+      base::MessageLoopProxy* target_loop,
+      const GetPluginsCallback& callback);
 #endif
 
   // Binding directly to GetAllowedPluginForOpenChannelToPlugin() isn't possible