Use fake Input Device Settings with chrome://device-emulator

chrome/chrome_tests_unit.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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       # histograms.xml is analyzed by AboutFlagsHistogramTest, so this
       # dependency is needed to make commit bots run unit_tests on
       # histograms.xml changes.
       '../tools/metrics/histograms/histograms.xml',
@@ skipping 1982 matching lines @@
             'browser/chromeos/policy/fake_consumer_management_service.cc',
             'browser/chromeos/policy/fake_consumer_management_service.h',
             'browser/chromeos/policy/fake_device_cloud_policy_initializer.cc',
             'browser/chromeos/policy/fake_device_cloud_policy_initializer.h',
             'browser/chromeos/policy/fake_device_cloud_policy_manager.cc',
             'browser/chromeos/policy/fake_device_cloud_policy_manager.h',
             'browser/chromeos/policy/stub_enterprise_install_attributes.cc',
             'browser/chromeos/policy/stub_enterprise_install_attributes.h',
             'browser/chromeos/settings/device_settings_test_helper.cc',
             'browser/chromeos/settings/device_settings_test_helper.h',
-            'browser/chromeos/system/fake_input_device_settings.cc',
-            'browser/chromeos/system/fake_input_device_settings.h',
           ],
+          'configurations': {
+            'Release': {
+              'sources': [

[michaelpg, 2016/06/03 16:18:34]

With 'sources' inside a 'variables' dictionary, GYP doesn't fail, but the
sources aren't built into the resulting library (so it seems the sources
variable is ignored here rather than propagated).

+                # Note: sources list duplicated in GN build.
+                'browser/chromeos/system/fake_input_device_settings.cc',
+                'browser/chromeos/system/fake_input_device_settings.h',
+              ],
+            },
+            'Debug': {
+              'conditions': [
+                ['buildtype=="Official"', {
+                  'sources': [
+                    # Note: sources list duplicated in GN build.
+                    'browser/chromeos/system/fake_input_device_settings.cc',
+                    'browser/chromeos/system/fake_input_device_settings.h',
+                  ],
+                }],
+              ],
+            }
+          },
         }],
         ['use_aura==1', {
           'sources': [
             'test/base/test_browser_window_aura.cc',
             'test/base/test_browser_window_aura.h',
           ],
         }],
         ['use_ash==1', {
           'sources': [
             'test/base/default_ash_event_generator_delegate.cc',
@@ skipping 991 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }