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

chrome/browser/chromeos/BUILD.gn

Index: chrome/browser/chromeos/BUILD.gn
diff --git a/chrome/browser/chromeos/BUILD.gn b/chrome/browser/chromeos/BUILD.gn
index 6543d0b180570b01a74e33911bec9db5a91dd333..fb1cd9d02372cda9d1a6feed870a7a388b42353a 100644
--- a/chrome/browser/chromeos/BUILD.gn
+++ b/chrome/browser/chromeos/BUILD.gn
@@ -174,6 +174,12 @@ source_set("chromeos") {
   if (ui_compositor_image_transport) {
     deps += [ "//ui/gl" ]
   }
+
+  if (!is_official_build && is_debug) {
+    sources += rebase_path(gypi_values.browser_chromeos_non_official_sources,
+                           ".",
+                           "//chrome")
+  }
 }
 
 source_set("unit_tests") {