Set the chromium_code GYP variable

snapshot/snapshot.gyp

 # Copyright 2014 The Crashpad Authors. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
 # You may obtain a copy of the License at
 #
 #     http://www.apache.org/licenses/LICENSE-2.0
 #
 # Unless required by applicable law or agreed to in writing, software
 # distributed under the License is distributed on an "AS IS" BASIS,
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
 {
+  'includes': [
+    '../build/crashpad.gypi',
+  ],
   'targets': [
     {
       'target_name': 'snapshot',
       'type': 'static_library',
       'dependencies': [
         '../client/client.gyp:client',
         '../compat/compat.gyp:compat',
         '../third_party/mini_chromium/mini_chromium/base/base.gyp:base',
         '../util/util.gyp:util',
       ],
@@ skipping 125 matching lines @@
         'mac/mach_o_image_segment_reader_test.cc',
         'mac/process_reader_test.cc',
         'mac/process_types_test.cc',
         'mac/system_snapshot_mac_test.cc',
         'minidump/process_snapshot_minidump_test.cc',
         'win/system_snapshot_win_test.cc',
       ],
     },
   ],
 }