[translate] Fix shutdown race for translate ranker model loader.

components/translate/core/browser/ranker_model_loader_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 "components/translate/core/browser/ranker_model_loader.h"
 
 #include <deque>
 #include <initializer_list>
 #include <memory>
 #include <vector>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"

[groby-ooo-7-16, 2017/04/24 19:12:46]

Why does this need ref_counted.h?

[Roger McFarlane (Chromium), 2017/04/24 20:31:34]

Just something I noticed is used without being explicitly included.

 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_scheduler/post_task.h"
 #include "base/task_scheduler/task_scheduler.h"
 #include "base/test/scoped_feature_list.h"
 #include "base/test/scoped_task_scheduler.h"
 #include "base/test/test_simple_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/metrics/proto/translate_event.pb.h"
@@ skipping 167 matching lines @@
   return IsEqual(*copy_m1, *copy_m2);
 }
 
 bool RankerModelLoaderTest::DoLoaderTest(const base::FilePath& model_path,
                                          const GURL& model_url) {
   auto loader = base::MakeUnique<RankerModelLoader>(
       base::Bind(&RankerModelLoaderTest::ValidateModel, base::Unretained(this)),
       base::Bind(&RankerModelLoaderTest::OnModelAvailable,
                  base::Unretained(this)),
       model_path, model_url, "RankerModelLoaderTest");
-
-  loader->Start();
+  loader->NotifyOfRankerActivity();
   base::RunLoop().RunUntilIdle();
 
   return true;
 }
 
 void RankerModelLoaderTest::InitRemoteModels() {
   InitModel(remote_model_url_, base::Time(), base::TimeDelta(), &remote_model_);
   url_fetcher_factory_.SetFakeResponse(
       remote_model_url_, remote_model_.SerializeAsString(), net::HTTP_OK,
       net::URLRequestStatus::SUCCESS);
@@ skipping 151 matching lines @@
   validate_model_response_.push_back(RankerModelStatus::OK);
   validate_model_response_.push_back(RankerModelStatus::INCOMPATIBLE);
 
   ASSERT_TRUE(DoLoaderTest(expired_model_path_, remote_model_url_));
   ASSERT_EQ(2U, validated_models_.size());
   ASSERT_EQ(1U, available_models_.size());
   EXPECT_TRUE(IsEquivalent(*validated_models_[0], local_model_));
   EXPECT_TRUE(IsEquivalent(*validated_models_[1], remote_model_));
   EXPECT_TRUE(IsEquivalent(*available_models_[0], local_model_));
 }