Host fingerprint mojo service within the device service.

services/device/fingerprint/BUILD.gn

+# Copyright 2017 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.
+
+import("//build/config/features.gni")
+
+component("fingerprint") {
+  visibility = [ "//services/device:*" ]
+
+  sources = [
+    "fingerprint.h",
+    "fingerprint_export.h",
+    "fingerprint_impl_chromeos.cc",
+    "fingerprint_impl_chromeos.h",
+    "fingerprint_impl_default.cc",
+  ]
+
+  defines = [ "SERVICES_DEVICE_FINGERPRINT_IMPLEMENTATION" ]
+
+  deps = [
+    "//base",
+    "//mojo/public/cpp/bindings",
+  ]
+
+  if (is_chromeos) {

[Rahul Chaturvedi, 2017/02/27 22:26:43]

This looks a little backwards.

This would be a lot clearer if we had something like,

sources = [
  "fingerprint.h",
  "fingerprint_export.h"
]

if (is_chromeos) {
  sources += [
     "fingerprint_impl_chromeos.h",
     "fingerprint_impl_default.cc",
  ]
  deps += [ "//dbus" ]
} else {
  sources += [ "fingerprint_impl_default.cc" ]
}

[xiaoyinh(OOO Sep 11-29), 2017/02/28 00:32:48]

Done.

+    sources -= [ "fingerprint_impl_default.cc" ]
+    deps += [ "//dbus" ]
+  }
+
+  public_deps = [
+    "//services/device/public/interfaces",
+  ]
+}