[ObjC ARC] Converts ios/chrome/browser/ui/reader_mode:reader_mode to ARC.

ios/chrome/browser/ui/reader_mode/reader_mode_checker.mm

 // Copyright 2015 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.
 
 #import "ios/chrome/browser/ui/reader_mode/reader_mode_checker.h"
 
 #include "base/logging.h"
 #include "base/strings/sys_string_conversions.h"
 #include "components/dom_distiller/core/distillable_page_detector.h"
 #include "components/dom_distiller/core/experiments.h"
 #include "components/dom_distiller/core/page_features.h"
 #include "components/dom_distiller/core/url_utils.h"
 #include "components/grit/components_resources.h"
 #include "ios/web/public/web_state/js/crw_js_injection_evaluator.h"
+#include "ios/web/public/web_state/js/crw_js_injection_receiver.h"
 #include "ios/web/public/web_state/web_state.h"
 #include "ui/base/resource/resource_bundle.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 ReaderModeCheckerObserver::ReaderModeCheckerObserver(
     ReaderModeChecker* readerModeChecker)
     : readerModeChecker_(readerModeChecker) {
   DCHECK(readerModeChecker);
   readerModeChecker_->AddObserver(this);
 }
 
 ReaderModeCheckerObserver::~ReaderModeCheckerObserver() {
   readerModeChecker_->RemoveObserver(this);
 }
@@ skipping 129 matching lines @@
 
 void ReaderModeChecker::AddObserver(ReaderModeCheckerObserver* observer) {
   DCHECK(!observers_.HasObserver(observer));
   observers_.AddObserver(observer);
 }
 
 void ReaderModeChecker::RemoveObserver(ReaderModeCheckerObserver* observer) {
   DCHECK(observers_.HasObserver(observer));
   observers_.RemoveObserver(observer);
 }