[ObjC ARC] Converts ios/web:web to ARC.

ios/chrome/browser/native_app_launcher/native_app_navigation_controller_unittest.mm

 // Copyright 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 <memory>
 
 #include "base/bind.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/user_metrics.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 46 matching lines @@
     action_callback_ =
         base::Bind(&NativeAppNavigationControllerTest::OnUserAction,
                    base::Unretained(this));
     base::AddActionCallback(action_callback_);
 
     handler_called_counter_ = 0;
   }
 
   void TearDown() override {
     base::RemoveActionCallback(action_callback_);
+    controller_ = nil;
     ChromeWebTest::TearDown();
   }
 
   void SetExpectedActionName(const std::string& action_name) {
     expected_action_name_.reset(new std::string(action_name));
   }
 
   void OnUserAction(const std::string& action_name) {
     EXPECT_EQ(*expected_action_name_, action_name);
     handler_called_counter_++;
@@ skipping 121 matching lines @@
   DCHECK([[controller_ appsPossiblyBeingInstalled] count] == 2);
   [fakeManager setAppScheme:kMapsAppName];
   [controller_ removeAppFromNotification:notificationMaps];
   DCHECK([[controller_ appsPossiblyBeingInstalled] count] == 1);
   [fakeManager setAppScheme:kYoutubeAppName];
   [controller_ removeAppFromNotification:notificationYouTube];
   DCHECK([[controller_ appsPossiblyBeingInstalled] count] == 0);
 }
 
 }  // namespace