[iOS] Add new feature flag for showing Reading list in Spotlight.

Bug: none
Change-Id: I7da940b28091dee61cca874d5c4950abc652b7da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4271190
Auto-Submit: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Louis Romero <lpromero@google.com>
Commit-Queue: Louis Romero <lpromero@google.com>
Cr-Commit-Position: refs/heads/main@{#1107819}

chrome/browser/flag-metadata.json

@@ -6538,6 +6538,14 @@
     ],
     "expiry_milestone": 115
   },
+  {
+    "name": "spotlight-reading-list-source",
+    "owners": [
+      "bling-flags@google.com",
+      "stkhapugin"
+    ],
+    "expiry_milestone": 120
+  },
   {
     "name": "start-surface",
     "owners": [ "gogerald", "bling-flags@google.com" ],

ios/chrome/browser/flags/about_flags.mm

@@ -1359,6 +1359,10 @@ const flags_ui::FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kFeedExperimentTaggingName,
      flag_descriptions::kFeedExperimentTaggingDescription, flags_ui::kOsIos,
      FEATURE_VALUE_TYPE(kEnableFeedExperimentTagging)},
+    {"spotlight-reading-list-source",
+     flag_descriptions::kSpotlightReadingListSourceName,
+     flag_descriptions::kSpotlightReadingListSourceDescription,
+     flags_ui::kOsIos, FEATURE_VALUE_TYPE(kSpotlightReadingListSource)},
 };
 
 bool SkipConditionalFeatureEntry(const flags_ui::FeatureEntry& entry) {

ios/chrome/browser/flags/ios_chrome_flag_descriptions.cc

@@ -811,6 +811,10 @@ const char kSmartSortingPriceTrackingDestinationDescription[] =
     "Adds the Price Tracking destination (with Smart Sorting) to the "
     "new overflow menu.";
 
+const char kSpotlightReadingListSourceName[] = "Show Reading List in Spotlight";
+const char kSpotlightReadingListSourceDescription[] =
+    "Donate Reading List items to iOS Search Engine Spotlight";
+
 const char kNewOverflowMenuShareChromeActionName[] =
     "Share Chrome App action in the new overflow menu";
 const char kNewOverflowMenuShareChromeActionDescription[] =

ios/chrome/browser/flags/ios_chrome_flag_descriptions.h

@@ -713,6 +713,10 @@ extern const char kSmartSortingNewOverflowMenuDescription[];
 extern const char kSmartSortingPriceTrackingDestinationName[];
 extern const char kSmartSortingPriceTrackingDestinationDescription[];
 
+// Title and description for th eflag to index Reading List items in Spotlight.
+extern const char kSpotlightReadingListSourceName[];
+extern const char kSpotlightReadingListSourceDescription[];
+
 // Title and description for the flag to enable the Share Chrome App action
 // in the new overflow menu.
 extern const char kNewOverflowMenuShareChromeActionName[];

ios/chrome/browser/ui/ui_feature_flags.cc

@@ -139,3 +139,7 @@ bool IsTabGridSortedByRecency() {
 BASE_FEATURE(kMultilineFadeTruncatingLabel,
              "MultilineFadeTruncatingLabel",
              base::FEATURE_DISABLED_BY_DEFAULT);
+
+BASE_FEATURE(kSpotlightReadingListSource,
+             "SpotlightReadingListSource",
+             base::FEATURE_DISABLED_BY_DEFAULT);

ios/chrome/browser/ui/ui_feature_flags.h

@@ -124,4 +124,7 @@ bool IsTabGridSortedByRecency();
 // Feature to enable multiline gradient support in fade truncating label.
 BASE_DECLARE_FEATURE(kMultilineFadeTruncatingLabel);
 
+// Enables indexing Reading List items in Spotlight.
+BASE_DECLARE_FEATURE(kSpotlightReadingListSource);
+
 #endif  // IOS_CHROME_BROWSER_UI_UI_FEATURE_FLAGS_H_