Allow autoplay unmuted for WebAPK in the manifest scope

content/public/common/web_preferences.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_COMMON_WEB_PREFERENCES_H_
 #define CONTENT_PUBLIC_COMMON_WEB_PREFERENCES_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 209 matching lines @@
   float expensive_background_throttling_max_delay;
 
 #if defined(OS_ANDROID)
   bool text_autosizing_enabled;
   float font_scale_factor;
   float device_scale_adjustment;
   bool force_enable_zoom;
   bool fullscreen_supported;
   bool double_tap_to_zoom_enabled;
   bool user_gesture_required_for_media_playback;
+  std::string media_playback_gesture_whitelist_scope;
   GURL default_video_poster_url;
   bool support_deprecated_target_density_dpi;
   bool use_legacy_background_size_shorthand_behavior;
   bool wide_viewport_quirk;
   bool use_wide_viewport;
   bool force_zero_layout_height;
   bool viewport_meta_layout_size_quirk;
   bool viewport_meta_merge_content_quirk;
   bool viewport_meta_non_user_scalable_quirk;
   bool viewport_meta_zero_values_quirk;
@@ skipping 47 matching lines @@
   // chrome, except for the cases where it would require lots of extra work for
   // the embedder to use the same default value.
   WebPreferences();
   WebPreferences(const WebPreferences& other);
   ~WebPreferences();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_COMMON_WEB_PREFERENCES_H_