Make the authentication service remember selected usernames.

services/authentication/BUILD.gn

 # Copyright 2015 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("//mojo/public/tools/bindings/mojom.gni")
+
 if (is_android) {
   import("//services/android/rules.gni")
 
   mojo_android_java_application("authentication") {
     sources = [
       "src/org/chromium/mojo/authentication/AuthenticationApp.java",
       "src/org/chromium/mojo/authentication/AuthenticationServiceImpl.java",
     ]
 
     mojo_main = "org.chromium.mojo.authentication.AuthenticationApp"
 
     deps = [
+      ":interfaces_java",
       "//mojo/public/interfaces/application:application_java",
       "//mojo/public/java:application",
       "//mojo/services/authentication/public/interfaces:interfaces_java",
       "//services/android:bindings_java",
       "//third_party/android_tools:google_play_services_default_java",
     ]
   }
+
+  mojom("interfaces") {
+    sources = [
+      "authentication_impl_db.mojom",
+    ]
+  }
 }