[ObjC ARC] Converts ios/chrome/browser/test:perf_test_support to ARC.

ios/chrome/browser/test/perf_test_with_bvc_ios.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 "ios/chrome/browser/test/perf_test_with_bvc_ios.h"
 
 #import <UIKit/UIKit.h>
 
 #include "base/files/file_path.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/bookmarks/test/bookmark_test_helpers.h"
 #include "ios/chrome/browser/autocomplete/autocomplete_classifier_factory.h"
 #include "ios/chrome/browser/bookmarks/bookmark_model_factory.h"
 #include "ios/chrome/browser/browser_state/test_chrome_browser_state_manager.h"
 #include "ios/chrome/browser/search_engines/template_url_service_factory.h"
 #import "ios/chrome/browser/sessions/session_ios.h"
 #import "ios/chrome/browser/sessions/session_service_ios.h"
 #import "ios/chrome/browser/sessions/session_window_ios.h"
 #import "ios/chrome/browser/tabs/tab_model.h"
 #import "ios/chrome/browser/ui/browser_view_controller.h"
 #import "ios/chrome/browser/ui/browser_view_controller_dependency_factory.h"
 #import "ios/chrome/browser/ui/preload_controller.h"
 #import "ios/chrome/browser/web/chrome_web_client.h"
 #include "ios/public/provider/chrome/browser/chrome_browser_provider.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 // Subclass of PrerenderController so it isn't actually used. Using a mock for
 // this makes cleanup on shutdown simpler, by minimizing the number of profile
 // observers registered with the profiles.  The profile observers have to be
 // deallocated before the profiles themselves, but in practice it is very hard
 // to ensure that happens.  Also, for performance testing, not having the
 // PrerenderController makes the test far simpler to analyze.
 namespace {
 static GURL emptyGurl_ = GURL("foo", 3, url::Parsed(), false);
 }
 
@@ skipping 133 matching lines @@
   // NSAutoreleasePool can drain. This needs to be done before
   // |chrome_browser_state_| can be cleared. For tests that allocate more
   // objects, more runloop time may be required.
   if (slow_teardown_)
     SpinRunLoop(.5);
   PerfTest::TearDown();
 
   // The profiles can be deallocated only after the BVC has been deallocated.
   chrome_browser_state_.reset();
 }