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 eb2116888563836dcfe598379b9d8264866d59e2..eda42753f46e9489d0e93467c48098b51ac2d6b4 100644
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -186,6 +186,10 @@ 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