mandoline: Fix mandoline release build on Linux.

mojo/runner/child/native_apptest_target.cc

Index: mojo/runner/child/native_apptest_target.cc
diff --git a/mojo/runner/child/native_apptest_target.cc b/mojo/runner/child/native_apptest_target.cc
index a2d35325fb8152f793f3699d83ff4f49fe959d99..ebe8750d80916e681d1643373363003ce16b59a4 100644
--- a/mojo/runner/child/native_apptest_target.cc
+++ b/mojo/runner/child/native_apptest_target.cc
@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include <windows.h>
-
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/debug/stack_trace.h"
@@ -25,6 +23,10 @@
 #include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
 #include "third_party/mojo/src/mojo/edk/embedder/process_delegate.h"
 
+#if defined(OS_WIN)
+#include <windows.h>
+#endif
+
 namespace {
 
 class EDKState : public mojo::embedder::ProcessDelegate {