Nux Onboarding: get hard-coded module list from feature params instead.

In this CL, four FeatureParams were added.

These 2 are added for "os_win && google_chrome_build" when
kNuxOnboardingFeature is enabled:

kNuxOnboardingNewUserModules
kNuxOnboardingReturningUserModules

And 2 more are added for when the feature is force-enabled with
kNuxOnboardingForceEnabled on other platforms/non-branded build:

kNuxOnboardingForceEnabledNewUserModules
kNuxOnboardingForceEnabledReturningUserModules

Sample command line to test the changes:

./out/gn/chrome --user-data-dir=/tmp/debug_chrome_1 \
    --enable-features="NuxOnboardingForceEnabled<study" \
    --force-fieldtrials=study/g1 \
    --force-fieldtrial-params=study.g1:new-user-modules/nux-google-apps/returning-user-modules/nux-email

TBR=mpearson@chromium.org

Bug: 874153
Change-Id: I495e6492ee66ce20ec8bfad8743d20c9c55acf53
Reviewed-on: https://chromium-review.googlesource.com/c/1311659
Commit-Queue: Scott Chen <scottchen@chromium.org>
Reviewed-by: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604748}

chrome/browser/resources/welcome/onboarding_welcome/welcome_app.html

@@ -10,6 +10,7 @@
 <link rel="import" href="navigation_behavior.html">
 <link rel="import" href="set_as_default/nux_set_as_default.html">
 <link rel="import" href="set_as_default/nux_set_as_default_proxy.html">
+<link rel="import" href="shared/i18n_setup.html">
 <link rel="import" href="signin_view.html">
 
 <dom-module id="welcome-app">

chrome/browser/resources/welcome/onboarding_welcome/welcome_app.js

@@ -11,10 +11,21 @@
  */
 let NuxOnboardingModules;
 
-// This list needs to be updated if new modules that need step-indicators are
-// added.
-const MODELS_NEEDING_INDICATOR =
-    ['nux-email', 'nux-google-apps', 'nux-set-as-default'];
+/**
+ * This list needs to be updated if new modules need to be supported in the
+ * onboarding flow.
+ * @const {!Set<string>}
+ */
+const MODULES_WHITELIST = new Set(
+    ['nux-email', 'nux-google-apps', 'nux-set-as-default', 'signin-view']);
+
+/**
+ * This list needs to be updated if new modules that need step-indicators are
+ * added.
+ * @const {!Set<string>}
+ */
+const MODULES_NEEDING_INDICATOR =
+    new Set(['nux-email', 'nux-google-apps', 'nux-set-as-default']);
 
 Polymer({
   is: 'welcome-app',
@@ -27,12 +38,11 @@ Polymer({
   /** @private {!PromiseResolver} */
   defaultCheckPromise_: new PromiseResolver(),
 
-  // TODO(scottchen): instead of dummy, get data from finch/load time data.
   /** @private {NuxOnboardingModules} */
   modules_: {
-    'new-user':
-        ['nux-email', 'nux-google-apps', 'nux-set-as-default', 'signin-view'],
-    'returning-user': ['nux-set-as-default'],
+    'new-user': loadTimeData.getString('new_user_modules').split(','),
+    'returning-user':
+        loadTimeData.getString('returning_user_modules').split(','),
   },
 
   properties: {
@@ -113,20 +123,22 @@ Polymer({
             element.remove();
           });
 
-      let indicatorElementCount = 0;
-      for (let i = 0; i < modules.length; i++) {
-        if (MODELS_NEEDING_INDICATOR.includes(modules[i]))
-          indicatorElementCount++;
-      }
+      const indicatorElementCount = modules.reduce((count, module) => {
+        return count += MODULES_NEEDING_INDICATOR.has(module) ? 1 : 0;
+      }, 0);
 
       let indicatorActiveCount = 0;
       modules.forEach((elementTagName, index) => {
+        // Makes sure the module specified by the feature configuration is
+        // whitelisted.
+        assert(MODULES_WHITELIST.has(elementTagName));
+
         const element = document.createElement(elementTagName);
         element.id = 'step-' + (index + 1);
         element.setAttribute('slot', 'view');
         this.$.viewManager.appendChild(element);
 
-        if (MODELS_NEEDING_INDICATOR.includes(elementTagName)) {
+        if (MODULES_NEEDING_INDICATOR.has(elementTagName)) {
           element.indicatorModel = {
             total: indicatorElementCount,
             active: indicatorActiveCount++,

chrome/browser/ui/webui/welcome/nux/constants.cc

@@ -8,16 +8,16 @@
 
 namespace nux {
 
-extern const base::Feature kNuxEmailFeature{"NuxEmail",
-                                            base::FEATURE_DISABLED_BY_DEFAULT};
-
-extern const base::Feature kNuxGoogleAppsFeature{
-    "NuxGoogleApps", base::FEATURE_DISABLED_BY_DEFAULT};
-
-extern const base::Feature kNuxOnboardingFeature{
-    "NuxOnboarding", base::FEATURE_DISABLED_BY_DEFAULT};
-
-extern const char kNuxEmailUrl[] = "chrome://welcome/email";
-extern const char kNuxGoogleAppsUrl[] = "chrome://welcome/apps";
-
-}  // namespace nux
+const base::Feature kNuxOnboardingFeature{"NuxOnboarding",
+                                          base::FEATURE_DISABLED_BY_DEFAULT};
+
+// The value of these FeatureParam values should be a comma-delimited list
+// of element names whitelisted in the MODULES_WHITELIST list, defined in
+// chrome/browser/resources/welcome/onboarding_welcome/welcome_app.js
+const base::FeatureParam<std::string> kNuxOnboardingNewUserModules{
+    &kNuxOnboardingFeature, "new-user-modules",
+    "nux-email,nux-google-apps,nux-set-as-default,signin-view"};
+const base::FeatureParam<std::string> kNuxOnboardingReturningUserModules{
+    &kNuxOnboardingFeature, "returning-user-modules", "nux-set-as-default"};
+
+}  // namespace nux
\ No newline at end of file

chrome/browser/ui/webui/welcome/nux/constants.h

@@ -5,17 +5,19 @@
 #ifndef CHROME_BROWSER_UI_WEBUI_WELCOME_NUX_CONSTANTS_H_
 #define CHROME_BROWSER_UI_WEBUI_WELCOME_NUX_CONSTANTS_H_
 
+#include <string>
+#include "base/metrics/field_trial_params.h"
+
 namespace base {
 struct Feature;
 }  // namespace base
 
 namespace nux {
 
-extern const base::Feature kNuxEmailFeature;
-extern const base::Feature kNuxGoogleAppsFeature;
 extern const base::Feature kNuxOnboardingFeature;
-extern const char kNuxEmailUrl[];
-extern const char kNuxGoogleAppsUrl[];
+
+extern const base::FeatureParam<std::string> kNuxOnboardingNewUserModules;
+extern const base::FeatureParam<std::string> kNuxOnboardingReturningUserModules;
 
 }  // namespace nux
 

chrome/browser/ui/webui/welcome/nux_helper.cc

@@ -3,7 +3,10 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/welcome/nux_helper.h"
+#include "base/feature_list.h"
+#include "base/values.h"
 #include "build/build_config.h"
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/welcome/nux/constants.h"
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
@@ -14,6 +17,17 @@ namespace nux {
 const base::Feature kNuxOnboardingForceEnabled = {
     "NuxOnboardingForceEnabled", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// The value of these FeatureParam values should be a comma-delimited list
+// of element names whitelisted in the MODULES_WHITELIST list, defined in
+// chrome/browser/resources/welcome/onboarding_welcome/welcome_app.js
+const base::FeatureParam<std::string> kNuxOnboardingForceEnabledNewUserModules =
+    {&kNuxOnboardingForceEnabled, "new-user-modules",
+     "nux-email,nux-google-apps,nux-set-as-default,signin-view"};
+const base::FeatureParam<std::string>
+    kNuxOnboardingForceEnabledReturningUserModules = {
+        &kNuxOnboardingForceEnabled, "returning-user-modules",
+        "nux-set-as-default"};
+
 bool IsNuxOnboardingEnabled(Profile* profile) {
   if (base::FeatureList::IsEnabled(nux::kNuxOnboardingForceEnabled)) {
     return true;
@@ -33,4 +47,24 @@ bool IsNuxOnboardingEnabled(Profile* profile) {
 #endif  // defined(OS_WIN) && defined(GOOGLE_CHROME_BUILD)
   }
 }
+
+base::DictionaryValue GetNuxOnboardingModules(Profile* profile) {
+  // This function should not be called when nux onboarding feature is not on.
+  DCHECK(nux::IsNuxOnboardingEnabled(profile));
+
+  base::DictionaryValue modules;
+
+  if (base::FeatureList::IsEnabled(nux::kNuxOnboardingForceEnabled)) {
+    modules.SetString("new-user",
+                      kNuxOnboardingForceEnabledNewUserModules.Get());
+    modules.SetString("returning-user",
+                      kNuxOnboardingForceEnabledReturningUserModules.Get());
+  } else {  // This means nux::kNuxOnboardingFeature is enabled.
+    modules.SetString("new-user", kNuxOnboardingNewUserModules.Get());
+    modules.SetString("returning-user",
+                      kNuxOnboardingReturningUserModules.Get());
+  }
+
+  return modules;
+}
 }  // namespace nux

chrome/browser/ui/webui/welcome/nux_helper.h

@@ -5,16 +5,27 @@
 #ifndef CHROME_BROWSER_UI_WEBUI_WELCOME_NUX_HELPER_H_
 #define CHROME_BROWSER_UI_WEBUI_WELCOME_NUX_HELPER_H_
 
-#include "base/feature_list.h"
 #include "base/macros.h"
-#include "chrome/browser/profiles/profile.h"
+#include "base/metrics/field_trial_params.h"
+
+namespace base {
+class DictionaryValue;
+struct Feature;
+}  // namespace base
 
 class Profile;
 
 namespace nux {
 extern const base::Feature kNuxOnboardingForceEnabled;
 
+extern const base::FeatureParam<std::string>
+    kNuxOnboardingForceEnabledNewUserModules;
+extern const base::FeatureParam<std::string>
+    kNuxOnboardingForceEnabledReturningUserModules;
+
 bool IsNuxOnboardingEnabled(Profile* profile);
+
+base::DictionaryValue GetNuxOnboardingModules(Profile* profile);
 }  // namespace nux
 
 #endif  // CHROME_BROWSER_UI_WEBUI_WELCOME_NUX_HELPER_H_

chrome/browser/ui/webui/welcome/welcome_ui.cc

@@ -206,6 +206,14 @@ WelcomeUI::WelcomeUI(content::WebUI* web_ui, const GURL& url)
 
     // Add set-as-default onboarding module.
     web_ui->AddMessageHandler(std::make_unique<nux::SetAsDefaultHandler>());
+
+    html_source->AddString(
+        "new_user_modules",
+        nux::GetNuxOnboardingModules(profile).FindKey("new-user")->GetString());
+    html_source->AddString("returning_user_modules",
+                           nux::GetNuxOnboardingModules(profile)
+                               .FindKey("returning-user")
+                               ->GetString());
   } else if (kIsBranded && is_dice) {
     // Use special layout if the application is branded and DICE is enabled.
     html_source->AddLocalizedString("headerText", IDS_WELCOME_HEADER);