Implement event sender service for testing

sky/tools/tester/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.
 
 shared_library("tester") {
   output_name = "sky_tester"
 
   sources = [
     "test_harness_impl.cc",
     "test_harness_impl.h",
     "test_runner.cc",
     "test_runner.h",
     "tester.cc",
   ]
 
   deps = [
     "//base",
     "//mojo/application",
     "//mojo/converters/geometry",
     "//mojo/converters/input_events",
     "//mojo/public/c/system:for_shared_library",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/system",
     "//mojo/public/cpp/utility",
     "//mojo/services/public/cpp/view_manager",
     "//mojo/services/public/interfaces/input_events",
     "//mojo/services/window_manager:lib",
+    "//sky/services/testing:bindings",
     "//sky/viewer:bindings",
   ]
 }