mac/linux: rework plugin channel file descriptor creation

chrome/plugin/plugin_thread.cc

 // 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.
 
 #include "chrome/plugin/plugin_thread.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
@@ skipping 85 matching lines @@
     base::KillProcess(base::GetCurrentProcessHandle(), 0, /* wait= */ false);
 
   // Call this last because it deletes the ResourceDispatcher, which is used
   // in some of the above cleanup.
   // See http://code.google.com/p/chromium/issues/detail?id=8980
   ChildThread::CleanUp();
   lazy_tls.Pointer()->Set(NULL);
 }
 
 void PluginThread::OnCreateChannel(
-#if defined(OS_POSIX)
-    base::FileDescriptor socket,
-#endif
     int process_id,
     bool off_the_record) {
-  int fd = -1;
+  scoped_refptr<PluginChannel> channel =
+      PluginChannel::GetPluginChannel(process_id, owner_loop());
+  IPC::ChannelHandle channel_handle;
+  if (channel.get()) {
+    channel_handle.name = channel->channel_name();
 #if defined(OS_POSIX)
-  fd = socket.fd;
+    // On POSIX, pass the renderer-side FD. Also mark it as auto-close so that
+    // it gets closed after it has been sent.
+    int renderer_fd = channel->DisownRendererFd();
+    channel_handle.socket = base::FileDescriptor(renderer_fd, true);
 #endif
-  std::string channel_name;
-  scoped_refptr<PluginChannel> channel =
-      PluginChannel::GetPluginChannel(process_id, owner_loop(), fd);
-  if (channel.get()) {
-    channel_name = channel->channel_name();
     channel->set_off_the_record(off_the_record);
   }
 
-  Send(new PluginProcessHostMsg_ChannelCreated(channel_name));
+  Send(new PluginProcessHostMsg_ChannelCreated(channel_handle));
 }
 
 void PluginThread::OnPluginMessage(const std::vector<unsigned char> &data) {
   // We Add/Release ref here to ensure that something will trigger the
   // shutdown mechanism for processes started in the absence of renderer's
   // opening a plugin channel.
   ChildProcess::current()->AddRefProcess();
   ChromePluginLib *chrome_plugin = ChromePluginLib::Find(plugin_path_);
   if (chrome_plugin) {
     void *data_ptr = const_cast<void*>(reinterpret_cast<const void*>(&data[0]));
@@ skipping 64 matching lines @@
   }
 
   if (!result || net_error != net::OK)
     return false;
 
   *proxy_list = proxy_result;
   return true;
 }
 
 } // namespace webkit_glue