Fix a truncation warning in wts_session_process_delegate.cc.

remoting/host/win/wts_session_process_delegate.cc

Index: remoting/host/win/wts_session_process_delegate.cc
diff --git a/remoting/host/win/wts_session_process_delegate.cc b/remoting/host/win/wts_session_process_delegate.cc
index b0bc149505b67e58b76a51416344255c75fe7fd9..e9f1ef05993dd14892f227faf377bd0937bd286b 100644
--- a/remoting/host/win/wts_session_process_delegate.cc
+++ b/remoting/host/win/wts_session_process_delegate.cc
@@ -309,7 +309,8 @@ void WtsSessionProcessDelegate::Core::OnIOCompleted(
     case JOB_OBJECT_MSG_NEW_PROCESS: {
       caller_task_runner_->PostTask(
           FROM_HERE, base::Bind(&Core::OnProcessLaunchDetected, this,
-                                reinterpret_cast<base::ProcessId>(context)));
+                                static_cast<base::ProcessId>(
+                                    reinterpret_cast<uintptr_t>(context))));
       break;
     }
   }