Add flags to enable screen orientation lock for fullscreen video on Android.

media/base/media_switches.cc

Index: media/base/media_switches.cc
diff --git a/media/base/media_switches.cc b/media/base/media_switches.cc
index ed9c09b7eb2a499836d39bf0a0ff3597164ed97c..30db0bcc98fdccc26c136a4ee5ae84944acb275c 100644
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -181,6 +181,10 @@ const base::Feature kExternalClearKeyForTesting{
 // Replaces WPMA by the MediaPlayerRenderer for HLS and fallback playback.
 const base::Feature kAndroidMediaPlayerRenderer{
     "android-media-player-renderer", base::FEATURE_ENABLED_BY_DEFAULT};
+
+// Lock the screen orientation when a video goes fullscreen.
+const base::Feature kVideoFullscreenOrientationLock{
+    "VideoFullscreenOrientationLock", base::FEATURE_DISABLED_BY_DEFAULT};
 #endif
 
 }  // namespace media