Add "AllArticles" mode to Reader Mode heuristics

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"
@@ skipping 130 matching lines @@
   }
 
   switch (dom_distiller::GetDistillerHeuristicsType()) {
     case dom_distiller::DistillerHeuristicsType::NONE:
       is_distillable_ = Status::kSwitchMaybe;
       break;
     case dom_distiller::DistillerHeuristicsType::OG_ARTICLE:
       CheckIsDistillableOG(receiver);
       break;
     case dom_distiller::DistillerHeuristicsType::ADABOOST_MODEL:
+    case dom_distiller::DistillerHeuristicsType::ALL_ARTICLES:
       CheckIsDistillableDetector(receiver);
       break;
     case dom_distiller::DistillerHeuristicsType::ALWAYS_TRUE:
       is_distillable_ = Status::kSwitchPossible;
       break;
   }
 }
 
 void ReaderModeChecker::WebStateDestroyed() {
   is_distillable_ = Status::kSwitchNo;
 }
 
 void ReaderModeChecker::AddObserver(ReaderModeCheckerObserver* observer) {
   DCHECK(!observers_.HasObserver(observer));
   observers_.AddObserver(observer);
 }
 
 void ReaderModeChecker::RemoveObserver(ReaderModeCheckerObserver* observer) {
   DCHECK(observers_.HasObserver(observer));
   observers_.RemoveObserver(observer);
 }