Use Mojo pipes to signal sync IPC events

chrome/browser/printing/cloud_print/test/cloud_print_proxy_process_browsertest.cc

 // Copyright (c) 2012 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.
 
 // Create a service process that uses a Mock to respond to the browser in order
 // to test launching the browser using the cloud print policy check command
 // line switch.
 
 #include <stdint.h>
 
@@ skipping 32 matching lines @@
 #include "chrome/test/base/testing_profile.h"
 #include "chrome/test/base/testing_profile_manager.h"
 #include "components/syncable_prefs/testing_pref_service_syncable.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/common/content_paths.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "content/public/test/test_utils.h"
 #include "ipc/ipc_descriptors.h"
 #include "ipc/ipc_multiprocess_test.h"
 #include "ipc/ipc_switches.h"
+#include "mojo/edk/embedder/embedder.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/multiprocess_func_list.h"
 
 #if defined(OS_MACOSX)
 #include "chrome/common/mac/mock_launchd.h"
 #endif
 #if defined(OS_POSIX)
 #include "base/posix/global_descriptors.h"
 #endif
@@ skipping 178 matching lines @@
   if (!service_process_state_initialized)
     return kInitializationFailure;
 
   TestServiceProcess service_process;
   EXPECT_EQ(&service_process, g_service_process);
 
   // Takes ownership of the pointer, but we can use it since we have the same
   // lifetime.
   EXPECT_TRUE(service_process.Initialize(&main_message_loop, state));
 
+  // Needed for IPC.
+  mojo::edk::Init();
+
   MockServiceIPCServer server(&service_process,
                               service_process.io_task_runner(),
                               state->GetServiceProcessChannel(),
                               service_process.GetShutdownEventForTesting());
 
   // Here is where the expectations/mock responses need to be set up.
   set_expectations.Run(&server);
 
   EXPECT_TRUE(server.Init());
   EXPECT_TRUE(state->SignalReady(service_process.io_task_runner().get(),
@@ skipping 254 matching lines @@
   // LocalState for the BrowserProcess.  Must be created before profiles are
   // constructed.
   chrome::TestingIOThreadState testing_io_thread_state;
 
   base::Process process =
       Launch("CloudPrintMockService_StartEnabledWaitForQuit");
   WaitForConnect();
   ShutdownAndWaitForExitWithTimeout(std::move(process));
   content::RunAllPendingInMessageLoop();
 }