Add flag "distillability-dev" for distillability development

components/dom_distiller/core/dom_distiller_features.cc

 // 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.
 
 #include "components/dom_distiller/core/dom_distiller_features.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "components/dom_distiller/core/dom_distiller_switches.h"
 
 namespace dom_distiller {
 
 bool IsEnableDomDistillerSet() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableDomDistiller);
 }
 
+bool IsDistillabilityDevSet() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDistillabilityDev);
+}
+
 bool IsEnableSyncArticlesSet() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableSyncArticles);
 }
 
 }  // namespace dom_distiller