Provide access to the ID for the remoted Windows session in the network process

remoting/host/desktop_session_proxy.cc

 // 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.
 
 #include "remoting/host/desktop_session_proxy.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 182 matching lines @@
   IPC_END_MESSAGE_MAP()
 
   CHECK(handled) << "Received unexpected IPC type: " << message.type();
   return handled;
 }
 
 void DesktopSessionProxy::OnChannelConnected(int32_t peer_pid) {
   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 
   VLOG(1) << "IPC: network <- desktop (" << peer_pid << ")";
+
+#if defined(OS_WIN)
+  if (!ProcessIdToSessionId(peer_pid,
+                            reinterpret_cast<DWORD*>(&desktop_session_id_))) {
+    PLOG(ERROR) << "ProcessIdToSessionId() failed!";
+  }
+#endif  // defined(OS_WIN)
 }
 
 void DesktopSessionProxy::OnChannelError() {
   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 
   DetachFromDesktop();
 }
 
 bool DesktopSessionProxy::AttachToDesktop(
     base::Process desktop_process,
@@ skipping 33 matching lines @@
       screen_resolution_,
       virtual_terminal_));
 
   return true;
 }
 
 void DesktopSessionProxy::DetachFromDesktop() {
   DCHECK(caller_task_runner_->BelongsToCurrentThread());
 
   desktop_channel_.reset();
+  desktop_session_id_ = UINT32_MAX;
 
   if (desktop_process_.IsValid())
     desktop_process_.Close();
 
   shared_buffers_.clear();
 
   // Generate fake responses to keep the video capturer in sync.
   while (pending_capture_frame_requests_) {
     --pending_capture_frame_requests_;
     video_capturer_->OnCaptureResult(
@@ skipping 272 matching lines @@
 }
 
 // static
 void DesktopSessionProxyTraits::Destruct(
     const DesktopSessionProxy* desktop_session_proxy) {
   desktop_session_proxy->caller_task_runner_->DeleteSoon(FROM_HERE,
                                                          desktop_session_proxy);
 }
 
 }  // namespace remoting