Add more components_unittests to GN build

components/dom_distiller/core/BUILD.gn

 # Copyright 2014 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.
 
 # GYP version: components/dom_distiller.gypi:dom_distiller_core
 source_set("core") {
   sources = [
     "../android/component_jni_registrar.cc",
     "../android/component_jni_registrar.h",
     "article_attachments_data.cc",
@@ skipping 100 matching lines @@
     "//testing/gmock",
     "//testing/gtest",
     "//url",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "article_entry_unittest.cc",
+    "distillable_page_detector_unittest.cc",
     "distilled_content_store_unittest.cc",
     "distilled_page_prefs_unittests.cc",
     "distiller_unittest.cc",
     "distiller_url_fetcher_unittest.cc",
     "dom_distiller_model_unittest.cc",
     "dom_distiller_request_view_base_unittest.cc",
     "dom_distiller_service_unittest.cc",
     "dom_distiller_store_unittest.cc",
     "page_features_unittest.cc",
     "task_tracker_unittest.cc",
@@ skipping 22 matching lines @@
 
   generate_jni("jni_headers") {
     sources = [
       "../android/java/src/org/chromium/components/dom_distiller/core/DistilledPagePrefs.java",
       "../android/java/src/org/chromium/components/dom_distiller/core/DomDistillerService.java",
       "../android/java/src/org/chromium/components/dom_distiller/core/DomDistillerUrlUtils.java",
     ]
     jni_package = "dom_distiller_core"
   }
 }