Update Windows It2Me to allow remote users to interact with elevated windows

remoting/host/win/launch_native_messaging_host_process.cc

Index: remoting/host/win/launch_native_messaging_host_process.cc
diff --git a/remoting/host/win/launch_native_messaging_host_process.cc b/remoting/host/win/launch_native_messaging_host_process.cc
index 9379e3ba8c3cd527bd77301bca4cd4245c10b45d..b6b4eae5eef4dea3df3e354959bde82edcf2b23b 100644
--- a/remoting/host/win/launch_native_messaging_host_process.cc
+++ b/remoting/host/win/launch_native_messaging_host_process.cc
@@ -12,6 +12,7 @@
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
+#include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/strings/stringprintf.h"
@@ -67,6 +68,11 @@ ProcessLaunchResult LaunchNativeMessagingHostProcess(
   DCHECK(read_handle);
   DCHECK(write_handle);
 
+  if (!base::PathExists(binary_path)) {
+    LOG(ERROR) << "Cannot find binary: " << binary_path.value();
+    return PROCESS_LAUNCH_RESULT_FAILED;
+  }
+
   // presubmit: allow wstring
   std::wstring user_sid;
   if (!base::win::GetUserSidString(&user_sid)) {