Ensure we don't load plugins on the IO thread

chrome/common/render_messages_internal.h

 // Copyright (c) 2009 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 header is meant to be included in multiple passes, hence no traditional
 // header guard.
 // See ipc_message_macros.h for explanation of the macros and passes.
 
 #include <string>
 #include <vector>
@@ skipping 887 matching lines @@
   // Returns a path to a plugin for the given url and mime type.  If there's
   // no plugin, an empty string is returned.
   IPC_SYNC_MESSAGE_CONTROL4_2(ViewHostMsg_GetPluginPath,
                               GURL /* url */,
                               GURL /* policy_url */,
                               std::string /* mime_type */,
                               std::string /* clsid */,
                               FilePath /* filename */,
                               std::string /* actual mime type for url */)
 
-  // Retrieve the data directory associated with the renderer's profile.
-  IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetDataDir,
-                              std::wstring /* data_dir_retval */)
-
   // Allows a chrome plugin loaded in a renderer process to send arbitrary
   // data to an instance of the same plugin loaded in the browser process.
   IPC_MESSAGE_CONTROL2(ViewHostMsg_PluginMessage,
                        FilePath /* plugin_path of plugin */,
                        std::vector<uint8> /* opaque data */)
 
   // Allows a chrome plugin loaded in a renderer process to send arbitrary
   // data to an instance of the same plugin loaded in the browser process.
   IPC_SYNC_MESSAGE_CONTROL2_1(ViewHostMsg_PluginSyncMessage,
                               FilePath /* plugin_path of plugin */,
@@ skipping 740 matching lines @@
   IPC_MESSAGE_CONTROL2(ViewHostMsg_DatabaseGetFileAttributes,
                        FilePath /* the name of the file */,
                        int32 /* a unique message ID */)
 
   // Asks the browser process to return the size of a DB file
   IPC_MESSAGE_CONTROL2(ViewHostMsg_DatabaseGetFileSize,
                        FilePath /* the name of the file */,
                        int32 /* a unique message ID */)
 
 IPC_END_MESSAGES(ViewHost)