[Explore Sites]: Add feature parameters to explore sites flag

Bug: 867488
Change-Id: Ibb67a81cfef555e93128ae395fe6a9f0081a45ed
Reviewed-on: https://chromium-review.googlesource.com/1157183
Commit-Queue: Cathy Li <chili@chromium.org>
Reviewed-by: Dmitry Titov <dimich@chromium.org>
Reviewed-by: Justin DeWitt <dewittj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#580303}

chrome/browser/BUILD.gn

@@ -2097,6 +2097,8 @@ jumbo_split_static_library("browser") {
       "android/explore_sites/catalog.h",
       "android/explore_sites/explore_sites_bridge.cc",
       "android/explore_sites/explore_sites_bridge.h",
+      "android/explore_sites/explore_sites_feature.cc",
+      "android/explore_sites/explore_sites_feature.h",
       "android/explore_sites/ntp_json_fetcher.cc",
       "android/explore_sites/ntp_json_fetcher.h",
       "android/explore_sites/url_util.cc",

chrome/browser/about_flags.cc

@@ -144,6 +144,7 @@
 #if defined(OS_ANDROID)
 #include "chrome/browser/android/chrome_feature_list.h"
 #include "chrome/browser/android/download/new_net_error_page_feature.h"
+#include "chrome/browser/android/explore_sites/explore_sites_feature.h"
 #else  // OS_ANDROID
 #include "chrome/browser/media/router/media_router_feature.h"
 #include "ui/message_center/public/cpp/features.h"
@@ -1206,6 +1207,12 @@ const FeatureEntry::FeatureVariation kNewNetErrorPageUIVariations[] = {
     {"Content Preview", &kNewNetErrorPageUIContentPreview, 1, nullptr},
     {"Content Preview + Auto download", &kNewNetErrorPageUIContentPreviewAutoDL,
      1, nullptr}};
+
+const FeatureEntry::FeatureParam kExploreSitesExperimental = {
+    chrome::android::explore_sites::kExploreSitesVariationParameterName,
+    chrome::android::explore_sites::kExploreSitesVariationExperimental};
+const FeatureEntry::FeatureVariation kExploreSitesVariations[] = {
+    {"Experimental", &kExploreSitesExperimental, 1, nullptr}};
 #endif  // defined(OS_ANDROID)
 
 // RECORDING USER METRICS FOR FLAGS:
@@ -1380,7 +1387,9 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(chrome::android::kContextualSearchUnityIntegration)},
     {"explore-sites", flag_descriptions::kExploreSitesName,
      flag_descriptions::kExploreSitesDescription, kOsAndroid,
-     FEATURE_VALUE_TYPE(chrome::android::kExploreSites)},
+     FEATURE_WITH_PARAMS_VALUE_TYPE(chrome::android::kExploreSites,
+                                    kExploreSitesVariations,
+                                    "ExploreSites")},
 #endif  // OS_ANDROID
     {"show-autofill-type-predictions",
      flag_descriptions::kShowAutofillTypePredictionsName,

chrome/browser/android/explore_sites/explore_sites_feature.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 "chrome/browser/android/explore_sites/explore_sites_feature.h"
+
+#include "base/feature_list.h"
+#include "base/metrics/field_trial_params.h"
+#include "chrome/browser/android/chrome_feature_list.h"
+
+namespace chrome {
+namespace android {
+namespace explore_sites {
+
+const char kExploreSitesVariationParameterName[] = "variation";
+
+const char kExploreSitesVariationExperimental[] = "experiment";
+
+ExploreSitesVariation GetExploreSitesVariation() {
+  if (base::FeatureList::IsEnabled(kExploreSites)) {
+    if (base::GetFieldTrialParamValueByFeature(
+            kExploreSites, kExploreSitesVariationParameterName) ==
+        kExploreSitesVariationExperimental) {
+      return ExploreSitesVariation::EXPERIMENT;
+    }
+    return ExploreSitesVariation::ENABLED;
+  }
+  return ExploreSitesVariation::DISABLED;
+}
+
+}  // namespace explore_sites
+}  // namespace android
+}  // namespace chrome

chrome/browser/android/explore_sites/explore_sites_feature.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 CHROME_BROWSER_ANDROID_EXPLORE_SITES_EXPLORE_SITES_FEATURE_H_
+#define CHROME_BROWSER_ANDROID_EXPLORE_SITES_EXPLORE_SITES_FEATURE_H_
+
+namespace chrome {
+namespace android {
+namespace explore_sites {
+
+extern const char kExploreSitesVariationParameterName[];
+
+extern const char kExploreSitesVariationExperimental[];
+
+enum class ExploreSitesVariation { ENABLED, EXPERIMENT, DISABLED };
+
+ExploreSitesVariation GetExploreSitesVariation();
+
+}  // namespace explore_sites
+}  // namespace android
+}  // namespace chrome
+
+#endif  // CHROME_BROWSER_ANDROID_EXPLORE_SITES_EXPLORE_SITES_FEATURE_H_

chrome/browser/android/explore_sites/explore_sites_feature_unittest.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 "chrome/browser/android/explore_sites/explore_sites_feature.h"
+
+#include <map>
+#include <string>
+
+#include "base/feature_list.h"
+#include "base/test/scoped_feature_list.h"
+#include "chrome/browser/android/chrome_feature_list.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chrome {
+namespace android {
+namespace explore_sites {
+
+TEST(ExploreSitesFeatureTest, ExploreSitesEnabled) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(kExploreSites);
+  EXPECT_EQ(ExploreSitesVariation::ENABLED, GetExploreSitesVariation());
+}
+
+TEST(ExploreSitesFeatureTest, ExploreSitesDisabled) {
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndDisableFeature(kExploreSites);
+  EXPECT_EQ(ExploreSitesVariation::DISABLED, GetExploreSitesVariation());
+}
+
+TEST(ExploreSitesFeatureTest, ExploreSitesEnabledWithExperiment) {
+  std::map<std::string, std::string> parameters;
+  parameters[kExploreSitesVariationParameterName] =
+      kExploreSitesVariationExperimental;
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeatureWithParameters(kExploreSites,
+                                                         parameters);
+  EXPECT_EQ(ExploreSitesVariation::EXPERIMENT, GetExploreSitesVariation());
+}
+
+TEST(ExploreSitesFeatureTest, ExploreSitesEnabledWithBogus) {
+  const char bogusParamValue[] = "bogus";
+  std::map<std::string, std::string> parameters;
+  parameters[kExploreSitesVariationParameterName] = bogusParamValue;
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeatureWithParameters(kExploreSites,
+                                                         parameters);
+  EXPECT_EQ(ExploreSitesVariation::ENABLED, GetExploreSitesVariation());
+}
+
+}  // namespace explore_sites
+}  // namespace android
+}  // namespace chrome

chrome/test/BUILD.gn

@@ -2304,6 +2304,7 @@ test("unit_tests") {
     "../browser/android/contextualsearch/contextual_search_field_trial_unittest.cc",
     "../browser/android/digital_asset_links/digital_asset_links_handler_unittest.cc",
     "../browser/android/download/download_manager_service_unittest.cc",
+    "../browser/android/explore_sites/explore_sites_feature_unittest.cc",
     "../browser/android/explore_sites/ntp_json_fetcher_unittest.cc",
     "../browser/android/history_report/data_observer_unittest.cc",
     "../browser/android/history_report/delta_file_backend_leveldb_unittest.cc",