MultiProcessTest: Update SpawnChild* to return a Process.

ipc/mojo/ipc_mojo_perftest.cc

 // 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.
 
 #include "base/lazy_instance.h"
 #include "ipc/ipc_perftest_support.h"
 #include "ipc/mojo/ipc_channel_mojo.h"
 #include "ipc/mojo/ipc_channel_mojo_host.h"
 #include "mojo/edk/embedder/test_embedder.h"
 
@@ skipping 22 matching lines @@
       const IPC::ChannelHandle& handle,
       base::TaskRunner* runner) override {
     host_.reset(new IPC::ChannelMojoHost(task_runner()));
     return IPC::ChannelMojo::CreateServerFactory(host_->channel_delegate(),
                                                  handle);
   }
 
   bool DidStartClient() override {
     bool ok = IPCTestBase::DidStartClient();
     DCHECK(ok);
-    host_->OnClientLaunched(client_process());
+    host_->OnClientLaunched(client_process().Handle());
     return ok;
   }
 
   void set_io_thread_task_runner(base::TaskRunner* runner) {
     io_thread_task_runner_ = runner;
   }
 
  private:
   base::TaskRunner* io_thread_task_runner_;
   scoped_ptr<IPC::ChannelMojoHost> host_;
@@ skipping 34 matching lines @@
                                IPC::Channel::MODE_CLIENT,
                                listener));
 }
 
 MULTIPROCESS_IPC_TEST_CLIENT_MAIN(PerformanceClient) {
   MojoTestClient client;
   return client.RunMain();
 }
 
 }  // namespace