Split the field trial setup code into desktop and mobile files.

chrome/chrome_browser.gypi

 # Copyright 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 309 matching lines @@
         'browser/certificate_viewer.cc',
         'browser/certificate_viewer.h',
         'browser/character_encoding.cc',
         'browser/character_encoding.h',
         'browser/chrome_net_benchmarking_message_filter.cc',
         'browser/chrome_net_benchmarking_message_filter.h',
         'browser/chrome_browser_application_mac.h',
         'browser/chrome_browser_application_mac.mm',
         'browser/chrome_browser_field_trials.cc',
         'browser/chrome_browser_field_trials.h',
+        'browser/chrome_browser_field_trials_desktop.cc',
+        'browser/chrome_browser_field_trials_desktop.h',
+        'browser/chrome_browser_field_trials_mobile.cc',
+        'browser/chrome_browser_field_trials_mobile.h',
         'browser/chrome_browser_main.cc',
         'browser/chrome_browser_main.h',
         'browser/chrome_browser_main_android.cc',
         'browser/chrome_browser_main_android.h',
         'browser/chrome_browser_main_extra_parts.h',
         'browser/chrome_browser_main_linux.cc',
         'browser/chrome_browser_main_linux.h',
         'browser/chrome_browser_main_mac.h',
         'browser/chrome_browser_main_mac.mm',
         'browser/chrome_browser_main_posix.cc',
@@ skipping 2281 matching lines @@
         }],
         ['enable_session_service!=1', {
           'sources!': [
             'browser/sessions/session_restore.cc',
             'browser/sessions/session_service.cc',
             'browser/sessions/session_service.h',
             'browser/sessions/session_service_factory.cc',
             'browser/sessions/session_service_factory.h',
           ],
         }],
-        ['OS!="android" and OS!="ios"', {
+        ['OS=="android" or OS=="ios"', {
           'sources!': [
+            'browser/chrome_browser_field_trials_desktop.cc',
+            'browser/chrome_browser_field_trials_desktop.h',
+          ],
+        }, {  # OS!="android" and OS!="ios"
+          'sources!': [
+            'browser/chrome_browser_field_trials_mobile.cc',
+            'browser/chrome_browser_field_trials_mobile.h',
             'browser/metrics/variations/eula_accepted_notifier_mobile.cc',
             'browser/metrics/variations/eula_accepted_notifier_mobile.h',
             'browser/metrics/variations/variations_request_scheduler_mobile.cc',
             'browser/metrics/variations/variations_request_scheduler_mobile.h',
           ],
         }],
         ['OS=="android"', {
           'dependencies': [
             '../components/components.gyp:web_contents_delegate_android',
             'chrome_browser_jni_headers',
@@ skipping 408 matching lines @@
             'package_name': 'org/chromium/chrome/browser/ui/toolbar',
             'template_deps': ['browser/ui/toolbar/toolbar_model_security_level_list.h'],
           },
           'includes': [ '../build/android/java_cpp_template.gypi' ],
         },
       ],
      },
     ],
   ],
 }