Turns on use_mojo=1 for linux.

content/content_browsertests.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=="android"', {
       'variables': {
         'isolate_dependency_tracked': [
           '<(PRODUCT_DIR)/content_shell/assets/content_shell.pak',
         ],
@@ skipping 20 matching lines @@
           '<(PRODUCT_DIR)/content_shell.pak',
           '<(PRODUCT_DIR)/fonts.conf',
           '<(PRODUCT_DIR)/libclearkeycdm.so',
           '<(PRODUCT_DIR)/libclearkeycdmadapter.so',
           '<(PRODUCT_DIR)/libffmpegsumo.so',
           '<(PRODUCT_DIR)/plugins/libtest_netscape_plugin.so',
           '<(PRODUCT_DIR)/plugins/libnpapi_test_plugin.so',
         ],
       },
     }],
+    ['OS=="linux" and use_mojo==1', {
+      'variables': {
+        'isolate_dependency_tracked': [
+          '<(PRODUCT_DIR)/lib/libmojo_system.so',
+        ],
+      },
+    }],
     ['OS=="linux" or OS=="mac" or OS=="win"', {
       'variables': {
         'isolate_dependency_tracked': [
           '../testing/test_env.py',
           '<(PRODUCT_DIR)/content_browsertests<(EXECUTABLE_SUFFIX)',
         ],
         'isolate_dependency_untracked': [
           '../net/tools/testserver/',
           '../third_party/WebKit/Tools/Scripts/',
           '../third_party/lighttpd/',
@@ skipping 35 matching lines @@
           '<(PRODUCT_DIR)/clearkeycdm.dll',
           '<(PRODUCT_DIR)/clearkeycdmadapter.dll',
           '<(PRODUCT_DIR)/content_shell.pak',
           '<(PRODUCT_DIR)/plugins/np_test_netscape_plugin.dll',
           '<(PRODUCT_DIR)/plugins/npapi_test_plugin.dll',
         ],
       },
     }],
   ],
 }