Forcibly clear worker ref counts on shutdown.

chrome/browser/predictors/resource_prefetch_predictor_tables_unittest.cc

 // Copyright 2014 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 <set>
 #include <utility>
 #include <vector>
 
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/predictors/predictor_database.h"
 #include "chrome/browser/predictors/resource_prefetch_predictor_tables.h"
 #include "chrome/test/base/testing_profile.h"
-#include "content/public/test/test_browser_thread.h"
+#include "content/public/test/test_browser_thread_bundle.h"
 #include "net/base/request_priority.h"
 #include "sql/statement.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace predictors {
 
 class ResourcePrefetchPredictorTablesTest : public testing::Test {
  public:
   ResourcePrefetchPredictorTablesTest();
   ~ResourcePrefetchPredictorTablesTest() override;
   void SetUp() override;
   void TearDown() override;
 
  protected:
   void ReopenDatabase();
   void TestGetAllData();
   void TestUpdateData();
   void TestDeleteData();
   void TestDeleteSingleDataPoint();
   void TestDeleteAllData();
 
-  base::MessageLoop loop_;
-  content::TestBrowserThread db_thread_;
+  content::TestBrowserThreadBundle thread_bundle_;
   TestingProfile profile_;
   std::unique_ptr<PredictorDatabase> db_;
   scoped_refptr<ResourcePrefetchPredictorTables> tables_;
 
   using PrefetchDataMap = ResourcePrefetchPredictorTables::PrefetchDataMap;
 
  private:
   using ResourceRow = ResourcePrefetchPredictorTables::ResourceRow;
   using ResourceRows = std::vector<ResourceRow>;
   using PrefetchData = ResourcePrefetchPredictorTables::PrefetchData;
@@ skipping 36 matching lines @@
   void SetUp() override {
     // Write data to the table, and then reopen the db.
     ResourcePrefetchPredictorTablesTest::SetUp();
     ResourcePrefetchPredictorTablesTest::TearDown();
 
     ReopenDatabase();
   }
 };
 
 ResourcePrefetchPredictorTablesTest::ResourcePrefetchPredictorTablesTest()
-    : loop_(base::MessageLoop::TYPE_DEFAULT),
-      db_thread_(content::BrowserThread::DB, &loop_),
-      db_(new PredictorDatabase(&profile_)),
+    : db_(new PredictorDatabase(&profile_)),
       tables_(db_->resource_prefetch_tables()) {
   base::RunLoop().RunUntilIdle();
 }
 
 ResourcePrefetchPredictorTablesTest::~ResourcePrefetchPredictorTablesTest() {
 }
 
 void ResourcePrefetchPredictorTablesTest::SetUp() {
   tables_->DeleteAllData();
   InitializeSampleData();
@@ skipping 326 matching lines @@
 
 TEST_F(ResourcePrefetchPredictorTablesReopenTest, DeleteSingleDataPoint) {
   TestDeleteSingleDataPoint();
 }
 
 TEST_F(ResourcePrefetchPredictorTablesReopenTest, DeleteAllData) {
   TestDeleteAllData();
 }
 
 }  // namespace predictors