Turns on use_mojo=1 for linux.

build/common.gypi

 # Copyright (c) 2012 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 820 matching lines @@
         }, {
           'v8_optimized_debug%': 2,
         }],
 
         # Disable various features by default on embedded.
         ['embedded==1', {
           'remoting%': 0,
           'enable_printing%': 0,
         }],
 
-        ['OS=="win"', {
+        ['OS=="win" or (OS=="linux" and chromeos==0)', {
           'use_mojo%': 1,
         }],
       ],
 
       # Set this to 1 to enable use of concatenated impulse responses
       # for the HRTF panner in WebAudio.
       'use_concatenated_impulse_responses': 1,
 
       # You can set the variable 'use_official_google_api_keys' to 1
       # to use the Google-internal file containing official API keys
@@ skipping 4259 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }