Add flag for enabling/disabling video fullscreen detection

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 842be0120794dc72f1a79ddba416325620f14516..730cb114282a4f58fc364d6c222450f3504df60a 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/BUILD.gn
@@ -2565,6 +2565,8 @@ split_static_library("browser") {
       "android/activity_type_ids.cc",
       "android/activity_type_ids.h",
       "android/android_theme_resources.h",
+      "android/app_hooks.cc",
+      "android/app_hooks.h",
       "android/appmenu/app_menu_drag_helper.cc",
       "android/appmenu/app_menu_drag_helper.h",
       "android/background_sync_launcher_android.cc",
@@ -3929,6 +3931,7 @@ if (is_android) {
   generate_jni("jni_headers") {
     sources = [
       "../android/java/src/org/chromium/chrome/browser/AfterStartupTaskUtils.java",
+      "../android/java/src/org/chromium/chrome/browser/AppHooks.java",
       "../android/java/src/org/chromium/chrome/browser/ApplicationLifetime.java",
       "../android/java/src/org/chromium/chrome/browser/BackgroundSyncLauncher.java",
       "../android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java",