Prepare for removal of source_filter.gypi:

runtime/bin/utils_macos.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#include <errno.h>
-#include <netdb.h>
-#include <sys/time.h>
+#include "platform/globals.h"
+#if defined(TARGET_OS_MACOS)
+
+#include <errno.h>  // NOLINT
+#include <netdb.h>  // NOLINT
+#include <sys/time.h>  // NOLINT
 
 #include "bin/utils.h"
 #include "platform/assert.h"
 
 OSError::OSError() : sub_system_(kSystem), code_(0), message_(NULL) {
   set_sub_system(kSystem);
   set_code(errno);
   SetMessage(strerror(errno));
 }
 
@@ skipping 58 matching lines @@
 }
 
 int64_t TimerUtils::GetCurrentTimeMicros() {
   struct timeval tv;
   if (gettimeofday(&tv, NULL) < 0) {
     UNREACHABLE();
     return 0;
   }
   return (static_cast<int64_t>(tv.tv_sec) * 1000000) + tv.tv_usec;
 }
+
+#endif  // defined(TARGET_OS_MACOS)