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

mojo/application/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_chromium
 source_set("application") {
   sources = [
     "application_runner_chromium.cc",
     "application_runner_chromium.h",
   ]
 
   public_deps = [
-    "//mojo/application/public/cpp:application",
+    "//mojo/application/public/cpp",
   ]
   deps = [
     "//base",
     "//mojo/common",
     "//mojo/environment:chromium",
   ]
 }
 
 source_set("content_handler") {
   sources = [
@@ skipping 15 matching lines @@
   testonly = true
   sources = [
     "application_test_base_chromium.cc",
     "application_test_base_chromium.h",
     "application_test_main_chromium.cc",
   ]
 
   deps = [
     "//base",
     "//base/test:test_support",
-    "//mojo/application/public/cpp:application",
+    "//mojo/application/public/cpp",
     "//third_party/mojo/src/mojo/public/cpp/bindings",
     "//third_party/mojo/src/mojo/public/cpp/environment",
     "//third_party/mojo/src/mojo/public/cpp/system",
     "//testing/gtest",
   ]
 
   data_deps = []
   if (is_android) {
     data_deps += [ "//mojo/android" ]
   }
   if (!is_component_build) {
     data_deps += [ "//mojo/runner" ]
   }
 }