Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/gcm_driver/instance_id/instance_id_driver_unittest.cc

 // Copyright 2015 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 "components/gcm_driver/instance_id/instance_id_driver.h"
 
 #include <stddef.h>
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
+#include "base/test/scoped_task_environment.h"
 #include "components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.h"
 #include "components/gcm_driver/instance_id/instance_id.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 #if defined(OS_ANDROID)
 #include "components/gcm_driver/instance_id/instance_id_android.h"
 #include "components/gcm_driver/instance_id/scoped_use_fake_instance_id_android.h"
 #endif  // OS_ANDROID
 
 namespace instance_id {
@@ skipping 54 matching lines @@
 
   InstanceIDDriver* driver() const { return driver_.get(); }
 
  private:
   void GetIDCompleted(const std::string& id);
   void GetCreationTimeCompleted(const base::Time& creation_time);
   void DeleteIDCompleted(InstanceID::Result result);
   void GetTokenCompleted(const std::string& token, InstanceID::Result result);
   void DeleteTokenCompleted(InstanceID::Result result);
 
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   std::unique_ptr<FakeGCMDriverForInstanceID> gcm_driver_;
   std::unique_ptr<InstanceIDDriver> driver_;
 
 #if defined(OS_ANDROID)
   InstanceIDAndroid::ScopedBlockOnAsyncTasksForTesting block_async_;
   ScopedUseFakeInstanceIDAndroid use_fake_;
 #endif  // OS_ANDROID
 
   std::string id_;
   base::Time creation_time_;
   std::string token_;
   InstanceID::Result result_;
 
   bool async_operation_completed_;
   base::Closure async_operation_completed_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(InstanceIDDriverTest);
 };
 
 InstanceIDDriverTest::InstanceIDDriverTest()
-    : result_(InstanceID::UNKNOWN_ERROR),
-      async_operation_completed_(false) {
-}
+    : scoped_task_environment_(
+          base::test::ScopedTaskEnvironment::MainThreadType::UI),
+      result_(InstanceID::UNKNOWN_ERROR),
+      async_operation_completed_(false) {}
 
 InstanceIDDriverTest::~InstanceIDDriverTest() {
 }
 
 void InstanceIDDriverTest::SetUp() {
   gcm_driver_.reset(new FakeGCMDriverForInstanceID);
   RecreateInstanceIDDriver();
 }
 
 void InstanceIDDriverTest::TearDown() {
@@ skipping 246 matching lines @@
       GetToken(instance_id, kAuthorizedEntity1, kScope2, options);
   EXPECT_FALSE(new_token1.empty());
   EXPECT_NE(token1, new_token1);
 
   // The other token is not affected by the deletion.
   EXPECT_EQ(token2,
             GetToken(instance_id, kAuthorizedEntity2, kScope1, options));
 }
 
 }  // namespace instance_id