Turns on use_mojo=1 for linux.

chrome/chrome.isolate

 # Copyright (c) 2013 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.
 {
   'conditions': [
     ['OS=="linux"', {
       'variables': {
         'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/libffmpegsumo.so',
           '<(PRODUCT_DIR)/libosmesa.so',
           '<(PRODUCT_DIR)/libppGoogleNaClPluginChrome.so',
+          '<(PRODUCT_DIR)/lib/libmojo_system.so',
           '<(PRODUCT_DIR)/nacl_helper<(EXECUTABLE_SUFFIX)',
           '<(PRODUCT_DIR)/nacl_helper_bootstrap<(EXECUTABLE_SUFFIX)',
         ],
       },
     }],
     ['OS=="linux" or OS=="mac" or OS=="win"', {
       'variables': {
         'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/resources.pak',
         ],
@@ skipping 47 matching lines @@
           '<(PRODUCT_DIR)/osmesa.dll',
           '<(PRODUCT_DIR)/ppGoogleNaClPluginChrome.dll',
         ],
       },
     }],
   ],
   'includes': [
     '../third_party/icu/icu.isolate',
   ],
 }