Add support for building the Dart VM for Android OS.

runtime/platform/utils.h

 // 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.
 
 #ifndef PLATFORM_UTILS_H_
 #define PLATFORM_UTILS_H_
 
 #include "platform/assert.h"
 #include "platform/globals.h"
 
@@ skipping 154 matching lines @@
                                 intptr_t length) {
     return offset >= 0 &&
            count >= 0 &&
            length >= 0 &&
            count <= (length - offset);
   }
 };
 
 }  // namespace dart
 
-#if defined(TARGET_OS_LINUX)
+#if defined(TARGET_OS_ANDROID)
+#include "platform/utils_android.h"
+#elif defined(TARGET_OS_LINUX)
 #include "platform/utils_linux.h"
 #elif defined(TARGET_OS_MACOS)
 #include "platform/utils_macos.h"
 #elif defined(TARGET_OS_WINDOWS)
 #include "platform/utils_win.h"
 #else
 #error Unknown target os.
 #endif
 
 #endif  // PLATFORM_UTILS_H_