Add missing define for Mojo NaCl build on ChromeOS.

mojo/mojo_edk_nacl.gyp

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/common_untrusted.gypi',
@@ skipping 23 matching lines @@
         '../base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
         'mojo_public.gyp:mojo_public_system',
       ],
       'defines': [
         'MOJO_SYSTEM_IMPL_IMPLEMENTATION',
       ],
       'sources': [
         '<@(mojo_edk_ports_sources)',
         '<@(mojo_edk_system_impl_sources)',
       ],
+      'conditions': [
+        ['OS=="android" or chromeos==1', {
+          'defines': [
+            'MOJO_EDK_LEGACY_PROTOCOL',
+          ],
+        }],
+      ],
     },
     {
       'target_name': 'mojo_system_impl_nacl_nonsfi',
       'type': 'none',
       'variables': {
         'nacl_untrusted_build': 1,
         'nlib_target': 'libmojo_system_impl_nacl_nonsfi.a',
         'build_glibc': 0,
         'build_newlib': 0,
         'build_irt': 0,
@@ skipping 15 matching lines @@
       'conditions': [
         ['OS=="android" or chromeos==1', {
           'defines': [
             'MOJO_EDK_LEGACY_PROTOCOL',
           ],
         }],
       ],
     },
   ],
 }