Prepare for removal of source_filter.gypi:

runtime/bin/eventhandler_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 "platform/globals.h"
+#if defined(TARGET_OS_MACOS)
+
 #include "bin/eventhandler.h"
 
-#include <errno.h>
-#include <pthread.h>
-#include <stdio.h>
-#include <string.h>
-#include <sys/event.h>
-#include <unistd.h>
+#include <errno.h>  // NOLINT
+#include <pthread.h>  // NOLINT
+#include <stdio.h>  // NOLINT
+#include <string.h>  // NOLINT
+#include <sys/event.h>  // NOLINT
+#include <unistd.h>  // NOLINT
 
 #include "bin/dartutils.h"
 #include "bin/fdutils.h"
 #include "bin/log.h"
 #include "bin/utils.h"
 #include "platform/hashmap.h"
 #include "platform/thread.h"
 #include "platform/utils.h"
 
 
@@ skipping 385 matching lines @@
 void* EventHandlerImplementation::GetHashmapKeyFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return reinterpret_cast<void*>(fd + 1);
 }
 
 
 uint32_t EventHandlerImplementation::GetHashmapHashFromFd(intptr_t fd) {
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }
+
+#endif  // defined(TARGET_OS_MACOS)