Remove SimpleBroker and instead use the production broker implementation in tests.

mojo/edk/system/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("//testing/test.gni")
 import("../../../mojo/public/tools/bindings/mojom.gni")
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
@@ skipping 53 matching lines @@
     "message_pipe_dispatcher.h",
     "options_validation.h",
     "platform_handle_dispatcher.cc",
     "platform_handle_dispatcher.h",
     "raw_channel.cc",
     "raw_channel.h",
     "raw_channel_posix.cc",
     "raw_channel_win.cc",
     "shared_buffer_dispatcher.cc",
     "shared_buffer_dispatcher.h",
-    "simple_broker.cc",
-    "simple_broker.h",
     "simple_dispatcher.cc",
     "simple_dispatcher.h",
     "transport_data.cc",
     "transport_data.h",
     "waiter.cc",
     "waiter.h",
   ]
 
   defines = [
     "MOJO_SYSTEM_IMPL_IMPLEMENTATION",
@@ skipping 116 matching lines @@
     "../test:test_support",
     "//base",
     "//base/test:test_support",
     "//testing/gtest",
 
     # TODO(use_chrome_edk): temporary since the Mojo wrapper primitives are
     # declared in third party only for now.
     "//third_party/mojo/src/mojo/edk/system",
   ]
 }