🦋 [FeedPreview] Add feature flag for feed content preview feature

Add feature flag for feed content preview feature.

Bug: 1221369
Change-Id: I44e47bf7d7d501b9476cdae9a7acae57de7fcfb3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2971508
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Commit-Queue: Tina Wang <tinazwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#894402}

chrome/browser/flag-metadata.json

@@ -1730,6 +1730,11 @@
     "owners": [ "ambake@microsoft.com", "desktop-pwas-team@google.com" ],
     "expiry_milestone": 96
   },
+  {
+    "name": "enable-discover-feed-preview",
+    "owners": [ "tinazwang", "sczs" ],
+    "expiry_milestone": 99
+  },
   {
     "name": "enable-dns-proxy",
     "owners": [ "garrick", "jasongustaman", "cros-networking@google.com" ],

ios/chrome/browser/flags/about_flags.mm

@@ -390,6 +390,10 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kAutofillCreditCardUploadName,
      flag_descriptions::kAutofillCreditCardUploadDescription, flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(autofill::features::kAutofillUpstream)},
+    {"enable-discover-feed-preview",
+     flag_descriptions::kEnableDiscoverFeedPreviewName,
+     flag_descriptions::kEnableDiscoverFeedPreviewDescription, flags_ui::kOsIos,
+     FEATURE_VALUE_TYPE(kEnableDiscoverFeedPreview)},
     {"use-sync-sandbox", flag_descriptions::kSyncSandboxName,
      flag_descriptions::kSyncSandboxDescription, flags_ui::kOsIos,
      SINGLE_VALUE_TYPE_AND_VALUE(

ios/chrome/browser/flags/ios_chrome_flag_descriptions.cc

@@ -180,6 +180,10 @@ const char kEnableCloseAllTabsConfirmationDescription[] =
     "Enable showing an action sheet that asks for confirmation when 'Close "
     "All' button is tapped on the tab grid to avoid unwanted clearing.";
 
+const char kEnableDiscoverFeedPreviewName[] = "Enable discover feed preview";
+const char kEnableDiscoverFeedPreviewDescription[] =
+    "Enable showing a live preview for discover feed long-press menu.";
+
 const char kEnableExtendedSyncPromosCapabilityName[] =
     "Enables reading the extended sync promo account capability";
 const char kEnableExtendedSyncPromosCapabilityDescription[] =

ios/chrome/browser/flags/ios_chrome_flag_descriptions.h

@@ -159,6 +159,11 @@ extern const char kEnableAutofillAddressSavePromptDescription[];
 extern const char kEnableCloseAllTabsConfirmationName[];
 extern const char kEnableCloseAllTabsConfirmationDescription[];
 
+// Title and description for the flag to enable the discover feed live preview
+// in long-press feed context menu.
+extern const char kEnableDiscoverFeedPreviewName[];
+extern const char kEnableDiscoverFeedPreviewDescription[];
+
 // Title and description for the flag to enable reading the extended sync promo
 // account capability from IdentityKit libraries.
 extern const char kEnableExtendedSyncPromosCapabilityName[];

ios/chrome/browser/ui/ntp/new_tab_page_feature.h

@@ -11,10 +11,17 @@
 // Use IsRefactoredNTP() instead of this constant directly.
 extern const base::Feature kRefactoredNTP;
 
+// Feature flag to enable showing a live preview for discover feed when opening
+// the feed context menu.
+extern const base::Feature kEnableDiscoverFeedPreview;
+
 // Parameter to enable/disable the logging of the refactoredNTP.
 extern const char kRefactoredNTPLoggingEnabled[];
 
 // Whether the refactored NTP is used instead of the legacy one.
 bool IsRefactoredNTP();
 
+// Whether the discover feed content preview is shown in the context menu.
+bool IsDiscoverFeedPreviewEnabled();
+
 #endif  // IOS_CHROME_BROWSER_UI_NTP_NEW_TAB_PAGE_FEATURE_H_

ios/chrome/browser/ui/ntp/new_tab_page_feature.mm

@@ -15,6 +15,9 @@
 const base::Feature kRefactoredNTP{"RefactoredNTP",
                                    base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kEnableDiscoverFeedPreview{
+    "EnableDiscoverFeedPreview", base::FEATURE_DISABLED_BY_DEFAULT};
+
 const char kRefactoredNTPLoggingEnabled[] = "RefactoredNTPLoggingEnabled";
 
 bool IsRefactoredNTP() {
@@ -23,3 +26,7 @@ bool IsRefactoredNTP() {
   return base::FeatureList::IsEnabled(kRefactoredNTP) &&
          IsDiscoverFeedEnabled();
 }
+
+bool IsDiscoverFeedPreviewEnabled() {
+  return base::FeatureList::IsEnabled(kEnableDiscoverFeedPreview);
+}