Simplify mojo/application/public/cpp/BUILD.gn to call the target cpp instead of application.

mojo/shell/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("//third_party/mojo/src/mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 
 source_set("shell") {
   output_name = "mojo_shell"
   sources = [
@@ skipping 43 matching lines @@
   sources = [
     "application_manager_unittest.cc",
     "query_util_unittest.cc",
   ]
 
   deps = [
     ":shell",
     ":test_bindings",
     "//base",
     "//mojo/application",
-    "//mojo/application/public/cpp:application",
+    "//mojo/application/public/cpp",
     "//mojo/common",
     "//mojo/environment:chromium",
     "//third_party/mojo/src/mojo/edk/test:run_all_unittests",
     "//third_party/mojo/src/mojo/public/cpp/bindings",
     "//testing/gtest",
     "//url",
   ]
 }
 
 mojom("test_bindings") {
   sources = [
     "test.mojom",
   ]
 }