Add flags and experiment config for selecting triggering heuristics

components/dom_distiller.gypi

 # Copyright 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.
 
 {
   'conditions': [
     ['android_webview_build == 0', {
       'targets': [
         {
           # GN version: //components/dom_distiller/webui
@@ skipping 72 matching lines @@
             'dom_distiller/core/dom_distiller_constants.h',
             'dom_distiller/core/dom_distiller_model.cc',
             'dom_distiller/core/dom_distiller_model.h',
             'dom_distiller/core/dom_distiller_observer.h',
             'dom_distiller/core/dom_distiller_service.cc',
             'dom_distiller/core/dom_distiller_service.h',
             'dom_distiller/core/dom_distiller_service_android.cc',
             'dom_distiller/core/dom_distiller_service_android.h',
             'dom_distiller/core/dom_distiller_store.cc',
             'dom_distiller/core/dom_distiller_store.h',
+            'dom_distiller/core/dom_distiller_switches.cc',
+            'dom_distiller/core/dom_distiller_switches.h',
+            'dom_distiller/core/experiments.cc',
+            'dom_distiller/core/experiments.h',
             'dom_distiller/core/feedback_reporter.cc',
             'dom_distiller/core/feedback_reporter.h',
             'dom_distiller/core/font_family_list.h',
             'dom_distiller/core/page_features.cc',
             'dom_distiller/core/page_features.h',
             'dom_distiller/core/task_tracker.cc',
             'dom_distiller/core/task_tracker.h',
             'dom_distiller/core/theme_list.h',
             'dom_distiller/core/url_constants.cc',
             'dom_distiller/core/url_constants.h',
@@ skipping 163 matching lines @@
                 'template_deps': ['dom_distiller/core/theme_list.h'],
               },
               'includes': [ '../build/android/java_cpp_template.gypi' ],
             },
           ],
         }],
       ],
     }],
   ],
 }