Use mash::session::mojom::kServiceName instead of a hardcoded string

chrome/test/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.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/common/features.gni")
@@ skipping 1176 matching lines @@
     sources += [
       "base/browser_tests_main_chromeos.cc",
       "base/mash_browser_tests_main.cc",
       "base/mash_browser_tests_main.h",
       "base/mojo_test_connector.cc",
       "base/mojo_test_connector.h",
     ]
 
     deps += [
       "//mash/package",
+      "//mash/session/public/interfaces:constants",
       "//services/service_manager/background:lib",
     ]
 
     data_deps = [
       ":mash_browser_tests_catalog_copy",
       "//mash/session",
     ]
   } else {
     sources += [ "base/browser_tests_main.cc" ]
   }
@@ skipping 3985 matching lines @@
 }
 
 if (is_win) {
   loadable_module("conflicts_dll") {
     testonly = true
     sources = [
       "conflicts/conflicts_dll.cc",
     ]
   }
 }