Add flag "distillability-dev" for distillability development

components/dom_distiller/core/dom_distiller_features.cc

Index: components/dom_distiller/core/dom_distiller_features.cc
diff --git a/components/dom_distiller/core/dom_distiller_features.cc b/components/dom_distiller/core/dom_distiller_features.cc
index 3d44ddfb365cec2283c145192aefac499e07a59e..ee63be7d9a25d67f43078d587cc4cca47efde302 100644
--- a/components/dom_distiller/core/dom_distiller_features.cc
+++ b/components/dom_distiller/core/dom_distiller_features.cc
@@ -16,6 +16,11 @@ bool IsEnableDomDistillerSet() {
           switches::kEnableDomDistiller);
 }
 
+bool IsDistillabilityDevSet() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kDistillabilityDev);
+}
+
 bool IsEnableSyncArticlesSet() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableSyncArticles);