Prepare for removal of source_filter.gypi:

runtime/vm/virtual_memory_linux.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 "vm/globals.h"
+#if defined(TARGET_OS_LINUX)
+
 #include "vm/virtual_memory.h"
 
-#include <sys/mman.h>
-#include <sys/unistd.h>
-#include <unistd.h>
+#include <sys/mman.h>  // NOLINT
+#include <sys/unistd.h>  // NOLINT
+#include <unistd.h>  // NOLINT
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 
 namespace dart {
 
 // standard MAP_FAILED causes "error: use of old-style cast" as it
 // defines MAP_FAILED as ((void *) -1)
 #undef MAP_FAILED
 #define MAP_FAILED reinterpret_cast<void*>(-1)
@@ skipping 69 matching lines @@
       prot = PROT_READ | PROT_EXEC;
       break;
     case kReadWriteExecute:
       prot = PROT_READ | PROT_WRITE | PROT_EXEC;
       break;
   }
   return (mprotect(address(), size(), prot) == 0);
 }
 
 }  // namespace dart
+
+#endif  // defined(TARGET_OS_LINUX)