Add flag "distillability-dev" for distillability development

components/dom_distiller/core/url_utils.cc

Index: components/dom_distiller/core/url_utils.cc
diff --git a/components/dom_distiller/core/url_utils.cc b/components/dom_distiller/core/url_utils.cc
index cfe4fcb9a21398cec21c8f68c5cf8d9b13147cb7..a079bdc97b175a486f72fb008f2333c82fc32139 100644
--- a/components/dom_distiller/core/url_utils.cc
+++ b/components/dom_distiller/core/url_utils.cc
@@ -7,6 +7,7 @@
 #include <string>
 
 #include "base/guid.h"
+#include "components/dom_distiller/core/dom_distiller_features.h"
 #include "components/dom_distiller/core/url_constants.h"
 #include "grit/components_resources.h"
 #include "net/base/url_util.h"
@@ -64,7 +65,11 @@ std::string GetValueForKeyInUrlPathQuery(const std::string& path,
 }
 
 bool IsUrlDistillable(const GURL& url) {
-  return url.is_valid() && url.SchemeIsHTTPOrHTTPS();
+  if (!url.is_valid())
+    return false;
+  if (IsDistillabilityDevSet() && url.SchemeIsFile())
+    return true;
+  return url.SchemeIsHTTPOrHTTPS();
 }
 
 bool IsDistilledPage(const GURL& url) {