Adding an experimental flag to block autoplay with sound in cross-origin iframes

content/public/common/web_preferences.h

Index: content/public/common/web_preferences.h
diff --git a/content/public/common/web_preferences.h b/content/public/common/web_preferences.h
index 9702484f6eb0da70a52d612e79362f5821da64ad..a735ff17832bac9a529136814b032d467216b490 100644
--- a/content/public/common/web_preferences.h
+++ b/content/public/common/web_preferences.h
@@ -242,13 +242,18 @@ struct CONTENT_EXPORT WebPreferences {
   // Used by Android_WebView only to support legacy apps that inject script into
   // a top-level initial empty document and expect it to persist on navigation.
   bool resue_global_for_unowned_main_frame;
-  bool autoplay_muted_videos_enabled;
   ProgressBarCompletion progress_bar_completion;
   // Specifies default setting for spellcheck when the spellcheck attribute is
   // not explicitly specified.
   bool spellcheck_enabled_by_default;
 #endif
 
+  bool autoplay_muted_videos_enabled;
+
+#if !defined(OS_ANDROID)
+  bool user_gesture_required_for_media_playback_in_cross_origin_iframes;
+#endif
+
   // String that describes how media element autoplay behavior should be
   // affected by experiment.
   std::string autoplay_experiment_mode;