Don't compile in root certs on Android.

runtime/bin/io_impl_sources.gypi

 # 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.
 
 # This file contains some C++ sources for the dart:io library.  The other
 # implementation files are in builtin_impl_sources.gypi.
 {
   'sources': [
     'eventhandler.cc',
     'eventhandler.h',
@@ skipping 25 matching lines @@
     'platform_linux.cc',
     'platform_macos.cc',
     'platform_win.cc',
     'process.cc',
     'process.h',
     'process_android.cc',
     'process_linux.cc',
     'process_macos.cc',
     'process_win.cc',
     '../../third_party/root_certificates/root_certificates.cc',
+    'root_certificates_unsupported.cc',
     'secure_socket.h',
     'secure_socket_boringssl.cc',
     'secure_socket_boringssl.h',
     'secure_socket_macos.cc',
     'secure_socket_macos.h',
     'secure_socket_unsupported.cc',
     'socket.cc',
     'socket.h',
     'socket_android.cc',
     'socket_android.h',
@@ skipping 13 matching lines @@
   'conditions': [
     ['dart_io_support==1', {
       'conditions': [
         ['dart_io_secure_socket==1', {
           'sources!' : [
             'io_service_no_ssl.cc',
             'io_service_no_ssl.h',
             'secure_socket_unsupported.cc',
           ],
           'conditions': [
-            ['OS=="mac"', {
+            ['dart_io_ssl_builtin_roots==0 or OS=="mac"', {
               # On Mac, we use the system keystore, so do not compile in the
               # root certs.
-              'sources!': [
+              'sources!' : [
                 '../../third_party/root_certificates/root_certificates.cc',
               ],
+            }, { # else dart_io_ssl_builtin_roots == 1 and OS != mac.
+              'sources!' : [
+                'root_certificates_unsupported.cc',
+              ],
             }],
           ],
         }, {  # else dart_io_secure_socket == 0
           'sources!' : [
             '../../third_party/root_certificates/root_certificates.cc',
+            'root_certificates_unsupported.cc',
             'io_service.cc',
             'io_service.h',
             'secure_socket.h',
             'secure_socket_boringssl.cc',
             'secure_socket_boringssl.h',
             'secure_socket_macos.cc',
             'secure_socket_macos.h',
           ],
         }],
       ],
       'sources!' : [
         'filter_unsupported.cc',
         'io_service_unsupported.cc',
       ],
     },{  # else dart_io_support == 0
       'sources!' : [
         'filter.cc',
         'filter.h',
         'io_service.cc',
         'io_service.h',
         'io_service_no_ssl.cc',
         'io_service_no_ssl.h',
         '../../third_party/root_certificates/root_certificates.cc',
+        'root_certificates_unsupported.cc',
         'secure_socket.h',
         'secure_socket_boringssl.cc',
         'secure_socket_boringssl.h',
         'secure_socket_macos.cc',
         'secure_socket_macos.h',
       ],
     }],
   ],
 }