Loads CastEglPlatform implementation from shared library.

media/ozone/media_ozone_platform.cc

Index: media/ozone/media_ozone_platform.cc
diff --git a/media/ozone/media_ozone_platform.cc b/media/ozone/media_ozone_platform.cc
index dcbc2f250168ae75d779567469f50083d962f472..cda13962820c4221e5302cd5aa6e9ff46e52b232 100644
--- a/media/ozone/media_ozone_platform.cc
+++ b/media/ozone/media_ozone_platform.cc
@@ -32,6 +32,10 @@ MediaOzonePlatform* CreateMediaOzonePlatformCaca() {
   return new MediaOzonePlatformStub;
 }
 
+MediaOzonePlatform* CreateMediaOzonePlatformCast() {
+  return new MediaOzonePlatformStub;
+}
+
 MediaOzonePlatform* CreateMediaOzonePlatformDri() {
   return new MediaOzonePlatformStub;
 }