ui: Cleanup class/struct forward declarations

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 75ddccc04a534affd0fc33c5c79dbfe1c6b02180..2945d382d681705f3b5b3df0bcbdcd802c30bacd 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1651,6 +1651,10 @@ const FeatureEntry kFeatureEntries[] = {
     {"offline-bookmarks", IDS_FLAGS_OFFLINE_BOOKMARKS_NAME,
      IDS_FLAGS_OFFLINE_BOOKMARKS_DESCRIPTION, kOsAndroid,
      FEATURE_VALUE_TYPE(offline_pages::kOfflineBookmarksFeature)},
+    {"offline-pages-async-download",
+     IDS_FLAGS_OFFLINE_PAGES_ASYNC_DOWNLOAD_NAME,
+     IDS_FLAGS_OFFLINE_PAGES_ASYNC_DOWNLOAD_DESCRIPTION, kOsAndroid,
+     FEATURE_VALUE_TYPE(offline_pages::kOfflinePagesAsyncDownloadFeature)},
     {"offline-pages-background-loading",
      IDS_FLAGS_OFFLINE_PAGES_BACKGROUND_LOADING_NAME,
      IDS_FLAGS_OFFLINE_PAGES_BACKGROUND_LOADING_DESCRIPTION, kOsAndroid,
@@ -1684,7 +1688,7 @@ const FeatureEntry kFeatureEntries[] = {
      MULTI_VALUE_TYPE(kNtpSwitchToExistingTabChoices)},
     {"use-android-midi-api", IDS_FLAGS_USE_ANDROID_MIDI_API_NAME,
      IDS_FLAGS_USE_ANDROID_MIDI_API_DESCRIPTION, kOsAndroid,
-     SINGLE_VALUE_TYPE(switches::kUseAndroidMidiApi)},
+     FEATURE_VALUE_TYPE(midi::features::kMidiManagerAndroid)},
 #endif  // OS_ANDROID
 #if defined(OS_WIN)
     {"trace-export-events-to-etw", IDS_FLAGS_TRACE_EXPORT_EVENTS_TO_ETW_NAME,