Use ScopedTaskEnvironment instead of MessageLoopForUI in device tests.

device/u2f/u2f_sign_unittest.cc

 // Copyright 2017 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 <list>
 
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/test/test_io_thread.h"
 #include "device/base/mock_device_client.h"
 #include "device/hid/mock_hid_service.h"
 #include "device/test/test_device_client.h"
 #include "mock_u2f_device.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "u2f_sign.h"
 
 namespace device {
 class U2fSignTest : public testing::Test {
  public:
-  U2fSignTest() : io_thread_(base::TestIOThread::kAutoStart) {}
+  U2fSignTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        io_thread_(base::TestIOThread::kAutoStart) {}
 
   void SetUp() override {
     MockHidService* hid_service = device_client_.hid_service();
     hid_service->FirstEnumerationComplete();
   }
 
  protected:
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   base::TestIOThread io_thread_;
   device::MockDeviceClient device_client_;
 };
 
 class TestSignCallback {
  public:
   TestSignCallback()
       : callback_(base::Bind(&TestSignCallback::ReceivedCallback,
                              base::Unretained(this))) {}
   ~TestSignCallback() {}
@@ skipping 168 matching lines @@
   std::pair<U2fReturnCode, std::vector<uint8_t>>& response =
       cb.WaitForCallback();
   EXPECT_EQ(U2fReturnCode::SUCCESS, response.first);
   // Device that responded had no correct keys, so a registration response is
   // expected
   ASSERT_LT(static_cast<size_t>(0), response.second.size());
   EXPECT_EQ(static_cast<uint8_t>(MockU2fDevice::kRegister), response.second[0]);
 }
 
 }  // namespace device