Add a browser test for UtilityProcessHost.

content/browser/utility_process_host_impl_browsertest.cc

+// Copyright 2016 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/bind.h"
+#include "base/run_loop.h"
+#include "base/strings/utf_string_conversions.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/utility_process_host.h"
+#include "content/public/browser/utility_process_host_client.h"
+#include "content/public/common/service_registry.h"
+#include "content/public/test/content_browser_test.h"
+#include "content/public/test/content_browser_test_utils.h"
+#include "content/public/test/test_mojo_service.mojom.h"
+
+namespace content {
+
+class UtilityProcessHostImplBrowserTest : public ContentBrowserTest {
+ public:
+  void RunUtilityProcess() {
+    base::RunLoop run_loop;
+    done_closure_ = run_loop.QuitClosure();
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(
+            &UtilityProcessHostImplBrowserTest::RunUtilityProcessOnIOThread,
+            base::Unretained(this)));
+    run_loop.Run();
+  }
+
+ protected:
+  void RunUtilityProcessOnIOThread() {
+    UtilityProcessHost* host = UtilityProcessHost::Create(nullptr, nullptr);
+    host->SetName(base::ASCIIToUTF16("TestProcess"));
+    EXPECT_TRUE(host->Start());
+
+    ServiceRegistry* service_registry = host->GetServiceRegistry();
+    service_registry->ConnectToRemoteService(mojo::GetProxy(&service_));
+    service_->DoSomething(base::Bind(
+        &UtilityProcessHostImplBrowserTest::OnSomething,
+        base::Unretained(this)));
+  }
+
+  void OnSomething() {
+    service_.reset();
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE, done_closure_);
+  }
+
+  mojom::TestMojoServicePtr service_;
+  base::Closure done_closure_;
+};
+
+IN_PROC_BROWSER_TEST_F(UtilityProcessHostImplBrowserTest, LaunchProcess) {
+  RunUtilityProcess();
+}
+
+}  // namespace content