Reland: Introduce the devices Mojo app

mojo/application/public/cpp/BUILD.gn

 # Copyright 2014 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.
 
 # GYP version: mojo/mojo_base.gyp:mojo_application_base
 source_set("cpp") {
-  deps = [
+  public_deps = [
     ":sources",
     ":init_commandline",
   ]
 }
 
 # Like the target above, but without special commandline initialization that
 # apps use.
 source_set("cpp_for_chromium") {
-  deps = [
+  public_deps = [
     ":sources",
   ]
 }
 
 source_set("sources") {
   sources = [
     "app_lifetime_helper.h",
     "application_connection.h",
     "application_delegate.h",
     "application_impl.h",
@@ skipping 63 matching lines @@
   ]
 
   data_deps = []
   if (is_android) {
     data_deps += [ "//mojo/android" ]
   }
   if (!is_component_build) {
     data_deps += [ "//mojo/runner" ]
   }
 }