Revert of Tests: Simplify SequencedWorkerPoolOwner, call Shutdown on destructor.

chrome/browser/chromeos/extensions/external_cache_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 "chrome/browser/chromeos/extensions/external_cache.h"
 
 #include <map>
 #include <set>
 #include <string>
 
@@ skipping 52 matching lines @@
         content::BrowserThread::GetMessageLoopProxyForThread(
             content::BrowserThread::IO));
     fetcher_factory_.reset(new net::TestURLFetcherFactory());
 
     pool_owner_.reset(
         new base::SequencedWorkerPoolOwner(3, "Background Pool"));
     background_task_runner_ = pool_owner_->pool()->GetSequencedTaskRunner(
         pool_owner_->pool()->GetNamedSequenceToken("background"));
   }
 
+  void TearDown() override {
+    pool_owner_->pool()->Shutdown();
+    base::RunLoop().RunUntilIdle();
+  }
+
   // ExternalCache::Delegate:
   void OnExtensionListsUpdated(const base::DictionaryValue* prefs) override {
     prefs_.reset(prefs->DeepCopy());
   }
 
   std::string GetInstalledExtensionVersion(const std::string& id) override {
     std::map<std::string, std::string>::iterator it =
         installed_extensions_.find(id);
     return it != installed_extensions_.end() ? it->second : std::string();
   }
@@ skipping 216 matching lines @@
   ASSERT_TRUE(provided_prefs()->GetDictionary(kTestExtensionId1, &entry1));
   EXPECT_TRUE(entry1->HasKey(
       extensions::ExternalProviderImpl::kExternalUpdateUrl));
   EXPECT_FALSE(entry1->HasKey(
       extensions::ExternalProviderImpl::kExternalCrx));
   EXPECT_FALSE(entry1->HasKey(
       extensions::ExternalProviderImpl::kExternalVersion));
 }
 
 }  // namespace chromeos