[Offline pages]: Add dino page experiment flag

Change-Id: I11e64d59194d6dbb52dd0b6f3ff2fefa8f796608
Reviewed-on: https://chromium-review.googlesource.com/999010Reviewed-by: Peter Williamson <petewil@chromium.org>
Commit-Queue: Cathy Li <chili@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550091}

chrome/browser/about_flags.cc

@@ -2357,6 +2357,12 @@ const FeatureEntry kFeatureEntries[] = {
      kOsAndroid,
      FEATURE_VALUE_TYPE(
          offline_pages::kOfflinePagesInDownloadHomeOpenInCctFeature)},
+    {"offline-pages-alternate-dino-page",
+     flag_descriptions::kOfflinePagesShowAlternateDinoPageName,
+     flag_descriptions::kOfflinePagesShowAlternateDinoPageDescription,
+     kOsAndroid,
+     FEATURE_VALUE_TYPE(
+         offline_pages::kOfflinePagesShowAlternateDinoPageFeature)},
 #endif  // OS_ANDROID
     {"disallow-doc-written-script-loads",
      flag_descriptions::kDisallowDocWrittenScriptsUiName,

chrome/browser/flag_descriptions.cc

@@ -2249,6 +2249,12 @@ const char kOfflinePagesSharingName[] = "Enables offline pages to be shared.";
 const char kOfflinePagesSharingDescription[] =
     "Enables the saved offline pages to be shared via other applications.";
 
+const char kOfflinePagesShowAlternateDinoPageName[] =
+    "Enable alternate dino page with more user capabilities.";
+const char kOfflinePagesShowAlternateDinoPageDescription[] =
+    "Enables the dino page to show more buttons and offer existing offline "
+    "content.";
+
 const char kOfflinePagesSvelteConcurrentLoadingName[] =
     "Enables concurrent background loading on svelte.";
 const char kOfflinePagesSvelteConcurrentLoadingDescription[] =

chrome/browser/flag_descriptions.h

@@ -1364,6 +1364,9 @@ extern const char kOfflinePagesRenovationsDescription[];
 extern const char kOfflinePagesSharingName[];
 extern const char kOfflinePagesSharingDescription[];
 
+extern const char kOfflinePagesShowAlternateDinoPageName[];
+extern const char kOfflinePagesShowAlternateDinoPageDescription[];
+
 extern const char kOfflinePagesSvelteConcurrentLoadingName[];
 extern const char kOfflinePagesSvelteConcurrentLoadingDescription[];
 

components/offline_pages/core/offline_page_feature.cc

@@ -72,6 +72,9 @@ const base::Feature kOfflinePagesInDownloadHomeOpenInCctFeature{
 const base::Feature kOfflinePagesCTSuppressNotificationsFeature{
     "OfflinePagesCTSuppressNotifications", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kOfflinePagesShowAlternateDinoPageFeature{
+    "OfflinePagesShowAlternateDinoPage", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const char kPrefetchingOfflinePagesExperimentsOption[] = "exp";
 
 bool IsOfflineBookmarksEnabled() {
@@ -155,6 +158,11 @@ bool IsOfflinePagesSuppressNotificationsEnabled() {
       kOfflinePagesCTSuppressNotificationsFeature);
 }
 
+bool ShouldShowAlternateDinoPage() {
+  return base::FeatureList::IsEnabled(
+      kOfflinePagesShowAlternateDinoPageFeature);
+}
+
 std::string GetPrefetchingOfflinePagesExperimentTag() {
   return base::GetFieldTrialParamValueByFeature(
       kPrefetchingOfflinePagesFeature,

components/offline_pages/core/offline_page_feature.h

@@ -27,6 +27,7 @@ extern const base::Feature kOfflinePagesDescriptivePendingStatusFeature;
 extern const base::Feature kOfflinePagesInDownloadHomeOpenInCctFeature;
 extern const base::Feature kOfflinePagesDescriptiveFailStatusFeature;
 extern const base::Feature kOfflinePagesCTSuppressNotificationsFeature;
+extern const base::Feature kOfflinePagesShowAlternateDinoPageFeature;
 
 // The parameter name used to find the experiment tag for prefetching offline
 // pages.
@@ -96,6 +97,9 @@ bool ShouldOfflinePagesInDownloadHomeOpenInCct();
 // tabs downloads.
 bool IsOfflinePagesSuppressNotificationsEnabled();
 
+// Controls whether we should show a dinosaur page with alternate UI.
+bool ShouldShowAlternateDinoPage();
+
 // Returns an experiment tag provided by the field trial. This experiment tag
 // will be included in a custom header in all requests sent to Offline Prefetch
 // Server. The server will use this this optional tag to decide how to process

components/offline_pages/core/offline_page_feature_unittest.cc

@@ -146,4 +146,15 @@ TEST(OfflinePageFeatureTest, OfflinePagesDescriptivePendingStatus) {
   EXPECT_TRUE(offline_pages::IsOfflinePagesDescriptivePendingStatusEnabled());
 }
 
+TEST(OfflinePageFeatureTest, AlternateDinoPage) {
+  // Disabled by default.
+  EXPECT_FALSE(offline_pages::ShouldShowAlternateDinoPage());
+
+  // Check if helper method works correctly when the features is enabled.
+  base::test::ScopedFeatureList scoped_feature_list;
+  scoped_feature_list.InitAndEnableFeature(
+      kOfflinePagesShowAlternateDinoPageFeature);
+  EXPECT_TRUE(offline_pages::ShouldShowAlternateDinoPage());
+}
+
 }  // namespace offline_pages

tools/metrics/histograms/enums.xml

@@ -26333,6 +26333,7 @@ from previous Chrome versions.
   <int value="-1314603238" label="ChromeHomePullToRefreshIphAtTop:enabled"/>
   <int value="-1311133348" label="VrBrowsingNativeAndroidUi:enabled"/>
   <int value="-1310737697" label="MaterialDesignSettings:enabled"/>
+  <int value="-1304957199" label="OfflinePagesShowAlternateDinoPage:enabled"/>
   <int value="-1302904242" label="enable-navigation-tracing"/>
   <int value="-1302859198" label="enable-stylus-virtual-keyboard:disabled"/>
   <int value="-1294050129" label="ContentFullscreen:disabled"/>
@@ -27296,6 +27297,7 @@ from previous Chrome versions.
   <int value="1036068554" label="enable-android-pay-integration-v2"/>
   <int value="1043334401" label="disable-slimming-paint-invalidation"/>
   <int value="1046878091" label="PasswordForceSaving:enabled"/>
+  <int value="1046981538" label="OfflinePagesShowAlternateDinoPage:disabled"/>
   <int value="1049885154" label="OfflinePagesPrefetching:disabled"/>
   <int value="1050048304" label="enable-font-cache-scaling"/>
   <int value="1050321458" label="new-profile-management"/>