Switch to using features API instead of fieldTrialTests for enabling new

chrome://dino modes

Bug: 846473
Change-Id: I739b7e40e735da10cc7d7cd75cf808e770bf817e
Reviewed-on: https://chromium-review.googlesource.com/1100455
Commit-Queue: Edward Jung <edwardjung@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567331}

components/error_page/common/BUILD.gn

@@ -6,6 +6,8 @@ static_library("common") {
   sources = [
     "error.cc",
     "error.h",
+    "error_page_features.cc",
+    "error_page_features.h",
     "error_page_params.cc",
     "error_page_params.h",
     "error_page_switches.cc",

components/error_page/common/error_page_features.cc

+// Copyright 2018 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/error_page/common/error_page_features.h"
+
+namespace error_page {
+namespace features {
+
+const base::Feature kDinoEasterEggBdayMode{"DinoEasterEggBdayMode",
+                                           base::FEATURE_DISABLED_BY_DEFAULT};
+
+}  // namespace features
+}  // namespace error_page
\ No newline at end of file

components/error_page/common/error_page_features.h

+// Copyright 2018 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.
+
+#ifndef COMPONENTS_ERROR_PAGE_COMMON_ERROR_PAGE_FEATURES_H_
+#define COMPONENTS_ERROR_PAGE_COMMON_ERROR_PAGE_FEATURES_H_
+
+#include "base/feature_list.h"
+
+namespace error_page {
+namespace features {
+
+// Defines all the features used by //components/error_page.
+
+// Enables or disables the offline dino easter egg bday mode.
+extern const base::Feature kDinoEasterEggBdayMode;
+
+}  // namespace features
+}  // namespace error_page
+
+#endif  // COMPONENTS_ERROR_PAGE_COMMON_ERROR_PAGE_FEATURES_H_

components/error_page/common/localized_error.cc

@@ -22,6 +22,7 @@
 #include "base/values.h"
 #include "build/build_config.h"
 #include "components/error_page/common/error.h"
+#include "components/error_page/common/error_page_features.h"
 #include "components/error_page/common/error_page_params.h"
 #include "components/error_page/common/error_page_switches.h"
 #include "components/error_page/common/net_error_info.h"
@@ -939,8 +940,8 @@ void LocalizedError::GetStrings(
   }
 
   if (command_line->HasSwitch(error_page::switches::kEnableEasterEggBdayMode) ||
-      base::FieldTrialList::FindFullName("EnableEasterEggBdayMode") ==
-          "enabled") {
+      base::FeatureList::IsEnabled(
+          error_page::features::kDinoEasterEggBdayMode)) {
     error_strings->SetBoolean("bdayMode", true);
   }