Revert of Ensure BrowserThread::CurrentlyOn is correct through MessageLoop teardown

chrome/browser/policy/cloud/component_cloud_policy_browsertest.cc

 // Copyright (c) 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 <string>
 
 #include "base/base64url.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ skipping 120 matching lines @@
 
     // And start with a signed-in user.
     SignInAndRegister();
 
     // The extension will receive an update event.
     EXPECT_TRUE(event_listener_->WaitUntilSatisfied());
 
     ExtensionBrowserTest::SetUpOnMainThread();
   }
 
-  void TearDownOnMainThread() override {
-    event_listener_.reset();
-    ExtensionBrowserTest::TearDownOnMainThread();
-  }
-
   scoped_refptr<const extensions::Extension> LoadExtension(
       const base::FilePath::CharType* path) {
     base::FilePath full_path;
     if (!PathService::Get(chrome::DIR_TEST_DATA, &full_path)) {
       ADD_FAILURE();
       return NULL;
     }
     scoped_refptr<const extensions::Extension> extension(
         ExtensionBrowserTest::LoadExtension(full_path.Append(path)));
     if (!extension.get()) {
@@ skipping 98 matching lines @@
   ExtensionTestMessageListener policy_listener1("{}", true);
   event_listener_->Reply("get-policy-Name");
   EXPECT_TRUE(policy_listener1.WaitUntilSatisfied());
 
   ExtensionTestMessageListener policy_listener2(kTestPolicy2JSON, false);
   policy_listener1.Reply("get-policy-Another");
   EXPECT_TRUE(policy_listener2.WaitUntilSatisfied());
 }
 
 IN_PROC_BROWSER_TEST_F(ComponentCloudPolicyTest, InstallNewExtension) {
-  event_listener_->Reply(std::string());
-  event_listener_.reset();
-
   EXPECT_TRUE(test_server_.UpdatePolicyData(
       dm_protocol::kChromeExtensionPolicyType, kTestExtension2, kTestPolicy2));
   // Installing a new extension doesn't trigger another policy fetch because
   // the server always sends down the list of all extensions that have policy.
   // Fetch now that the configuration has been updated and before installing
   // the extension.
   RefreshPolicies();
 
   ExtensionTestMessageListener result_listener("ok", false);
   result_listener.set_failure_message("fail");
@@ skipping 62 matching lines @@
   ExtensionTestMessageListener signin_policy_listener(kTestPolicyJSON, false);
   event_listener2.Reply("get-policy-Name");
   EXPECT_TRUE(signin_policy_listener.WaitUntilSatisfied());
 
   // And the cache is back.
   EXPECT_TRUE(base::PathExists(cache_path));
 }
 #endif
 
 }  // namespace policy