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

chrome/chrome_tests_unit.gypi

Index: chrome/chrome_tests_unit.gypi
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 963dbe056b132669e89084d9713db8a7553534e5..1df5e51da8b1b8316637e1e5debeb4023edbc204 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -2000,9 +2000,27 @@
             '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': [