Instantiate ScopedTaskEnvironment in net unittests.

net/disk_cache/disk_cache_test_base.cc

 // Copyright (c) 2012 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 "net/disk_cache/disk_cache_test_base.h"
 
 #include <utility>
 
 #include "base/files/file_util.h"
 #include "base/path_service.h"
@@ skipping 13 matching lines @@
 #include "net/disk_cache/simple/simple_index.h"
 #include "net/test/gtest_util.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using net::test::IsOk;
 
 DiskCacheTest::DiskCacheTest() {
   CHECK(temp_dir_.CreateUniqueTempDir());
   cache_path_ = temp_dir_.GetPath();
-  if (!base::MessageLoop::current())
-    message_loop_.reset(new base::MessageLoopForIO());
 }
 
 DiskCacheTest::~DiskCacheTest() {
 }
 
 bool DiskCacheTest::CopyTestCache(const std::string& name) {
   base::FilePath path;
   PathService::Get(base::DIR_SOURCE_ROOT, &path);
   path = path.AppendASCII("net");
   path = path.AppendASCII("data");
@@ skipping 306 matching lines @@
   if (size_)
     EXPECT_TRUE(cache_impl_->SetMaxSize(size_));
   if (new_eviction_)
     cache_impl_->SetNewEviction();
   cache_impl_->SetType(type_);
   cache_impl_->SetFlags(flags);
   net::TestCompletionCallback cb;
   int rv = cache_impl_->Init(cb.callback());
   ASSERT_THAT(cb.GetResult(rv), IsOk());
 }