Changing multiprocess test SpawnChild to return a struct.

mojo/edk/test/multiprocess_test_helper.cc

 // Copyright 2013 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.
 
 #include "mojo/edk/test/multiprocess_test_helper.h"
 
 #include <functional>
 #include <set>
 #include <utility>
 
@@ skipping 142 matching lines @@
       launch_type == LaunchType::NAMED_CHILD) {
     std::string pipe_token;
     pipe = process.CreateMessagePipe(&pipe_token);
     command_line.AppendSwitchASCII(kMojoPrimordialPipeToken, pipe_token);
   } else if (launch_type == LaunchType::PEER ||
              launch_type == LaunchType::NAMED_PEER) {
     peer_token_ = mojo::edk::GenerateRandomToken();
     pipe = ConnectToPeerProcess(std::move(server_handle), peer_token_);
   }
 
-  test_child_ =
+  base::SpawnChildResult result =
       base::SpawnMultiProcessTestChild(test_child_main, command_line, options);
+  test_child_ = std::move(result.process);
   if (launch_type == LaunchType::CHILD || launch_type == LaunchType::PEER)
     channel.ChildProcessLaunched();
 
   if (launch_type == LaunchType::CHILD ||
       launch_type == LaunchType::NAMED_CHILD) {
     DCHECK(server_handle.is_valid());
     process.Connect(test_child_.Handle(), std::move(server_handle),
                     process_error_callback_);
   }
 
@@ skipping 71 matching lines @@
             ::testing::Test::HasNonfatalFailure()) ? 1 : 0;
   });
 }
 
 // static
 mojo::ScopedMessagePipeHandle MultiprocessTestHelper::primordial_pipe;
 
 }  // namespace test
 }  // namespace edk
 }  // namespace mojo