Use ScopedTaskEnvironment instead of MessageLoop in content unit tests.

content/child/indexed_db/webidbcursor_impl_unittest.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 "content/child/indexed_db/webidbcursor_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/values.h"
 #include "content/child/indexed_db/indexed_db_key_builders.h"
 #include "content/child/indexed_db/mock_webidbcallbacks.h"
 #include "content/child/thread_safe_sender.h"
 #include "content/common/indexed_db/indexed_db_key.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/WebKit/public/platform/WebData.h"
 
@@ skipping 96 matching lines @@
   WebIDBCursorImplTest() {
     null_key_.assignNull();
     indexed_db::mojom::CursorAssociatedPtr ptr;
     mock_cursor_ =
         base::MakeUnique<MockCursorImpl>(mojo::MakeIsolatedRequest(&ptr));
     cursor_ = base::MakeUnique<WebIDBCursorImpl>(
         ptr.PassInterface(), 1, base::ThreadTaskRunnerHandle::Get());
   }
 
  protected:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   WebIDBKey null_key_;
   std::unique_ptr<WebIDBCursorImpl> cursor_;
   std::unique_ptr<MockCursorImpl> mock_cursor_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(WebIDBCursorImplTest);
 };
 
 TEST_F(WebIDBCursorImplTest, PrefetchTest) {
   // Call continue() until prefetching should kick in.
@@ skipping 180 matching lines @@
   base::RunLoop().RunUntilIdle();
   EXPECT_EQ(1, mock_cursor_->reset_calls());
   EXPECT_EQ(1, mock_cursor_->last_used_count());
 
   cursor_.reset();
   base::RunLoop().RunUntilIdle();
   EXPECT_TRUE(mock_cursor_->destroyed());
 }
 
 }  // namespace content