[Media] Plumb a feature parameter for the background video keyframe distance.

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 245 matching lines @@
   // scale limits. These are set directly on the WebView so there's no analogue
   // in WebSettings.
   float default_minimum_page_scale_factor;
   float default_maximum_page_scale_factor;
 
   // Whether download UI should be hidden on this page.
   bool hide_download_ui;
 
   // If enabled, disabled video track when the video is in the background.
   bool background_video_track_optimization_enabled;
+  // If background video track optimization is enabled, don't disable video

[nasko, 2017/01/13 16:30:04]

nit: Keep the the style of the file and put an empty line above the comment.

[whywhat, 2017/01/13 21:10:54]

Done.

+  // track for videos with the average keyframe distance greater than this
+  // value (in seconds).
+  int max_keyframe_distance_to_disable_background_video_sec;

[DaleCurtis, 2017/01/13 20:34:13]

base::TimeDelta?

[whywhat, 2017/01/13 21:10:54]

Hm, I've no idea if the IPC macros will handle anything that's not a primitive
type or a string. Will try :)

 
   // Whether it is a presentation receiver.
   bool presentation_receiver;
 
   // We try to keep the default values the same as the default values in
   // 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_