[Media] Add a feature flag to pause bg video only players.

media/base/media_switches.cc

 // Copyright (c) 2012 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.
 
 #include "build/build_config.h"
 #include "media/base/media_switches.h"
 #include "ppapi/features/features.h"
 
 namespace switches {
 
@@ skipping 155 matching lines @@
       base::FEATURE_ENABLED_BY_DEFAULT
 #else
       base::FEATURE_DISABLED_BY_DEFAULT
 #endif
 };
 
 // Let video track be unselected when video is playing in the background.
 const base::Feature kBackgroundVideoTrackOptimization{
     "BackgroundVideoTrackOptimization", base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Let video without audio be paused when it is playing in the background.
+const base::Feature kBackgroundVideoPauseOptimization{
+    "BackgroundVideoPauseOptimization", base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Make MSE garbage collection algorithm more aggressive when we are under
 // moderate or critical memory pressure. This will relieve memory pressure by
 // releasing stale data from MSE buffers.
 const base::Feature kMemoryPressureBasedSourceBufferGC{
     "MemoryPressureBasedSourceBufferGC", base::FEATURE_DISABLED_BY_DEFAULT};
 
 // Use shared block-based buffering for media.
 const base::Feature kUseNewMediaCache{"use-new-media-cache",
                                       base::FEATURE_ENABLED_BY_DEFAULT};
 
@@ skipping 18 matching lines @@
 
 // An experimental feature to enable persistent-license type support in MediaDrm
 // when using Encrypted Media Extensions (EME) API.
 // TODO(xhwang): Remove this after feature launch. See http://crbug.com/493521
 const base::Feature kMediaDrmPersistentLicense{
     "MediaDrmPersistentLicense", base::FEATURE_DISABLED_BY_DEFAULT};
 
 #endif
 
 }  // namespace media