Media Remoting: Add feature to control enabling Media Remoting.

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 c7e02e2c39d8637983da8a9610feabf2618e2985..0eff23ae3eb8d67498f719cf65db58e9cffbf32b 100644
--- a/media/base/media_switches.cc
+++ b/media/base/media_switches.cc
@@ -174,4 +174,11 @@ const base::Feature kAndroidMediaPlayerRenderer{
     "android-media-player-renderer", base::FEATURE_DISABLED_BY_DEFAULT};
 #endif
 
+#if BUILDFLAG(ENABLE_MEDIA_REMOTING)
+// Enables to renderer and play back media on remote devices when the tab is
+// being mirrored and other conditions are met.
+const base::Feature kMediaRemoting{"media-remoting",
+                                   base::FEATURE_ENABLED_BY_DEFAULT};
+#endif
+
 }  // namespace media