Allow autoplay unmuted for WebAPK in the manifest scope

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 7e94deeb27ea4320354e888982104ce6e10ca620..635ddb64c631e2a6663cf4d3d6d04105179544d8 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -654,6 +654,10 @@ const char kMainFrameResizesAreOrientationChanges[] =
 const char kMaxUntiledLayerHeight[]         = "max-untiled-layer-height";
 const char kMaxUntiledLayerWidth[]          = "max-untiled-layer-width";
 
+// Disable gesture requirement for media playback in the specified whitelist.
+const char kMediaPlaybackGestureWhitelistScope[] =
+    "media-playback-gesture-whitelist-scope";
+
 // Sample memory usage with high frequency and store the results to the
 // Renderer.Memory histogram. Used in memory tests.
 const char kMemoryMetrics[]                 = "memory-metrics";