Add crypto_android.cc

runtime/bin/crypto_android.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 <fcntl.h>
 
 #include "bin/fdutils.h"
 #include "bin/crypto.h"
 
 
 bool Crypto::GetRandomBytes(intptr_t count, uint8_t* buffer) {
   intptr_t fd = TEMP_FAILURE_RETRY(open("/dev/urandom", O_RDONLY));
   if (fd < 0) return false;
   intptr_t bytes_read = read(fd, buffer, count);
   close(fd);
   return bytes_read == count;
 }