gpu: Make GPU command decoder know right format of a GPU video texture in Win.

media/video/video_decode_accelerator.cc

Index: media/video/video_decode_accelerator.cc
diff --git a/media/video/video_decode_accelerator.cc b/media/video/video_decode_accelerator.cc
index a72912cf3059ac777c9314b99fc286baf8d09ad9..9b7bd451351063493fc639327afee09e8aa1540e 100644
--- a/media/video/video_decode_accelerator.cc
+++ b/media/video/video_decode_accelerator.cc
@@ -4,6 +4,7 @@
 
 #include "media/video/video_decode_accelerator.h"
 
+#include <GLES2/gl2.h>
 #include "base/logging.h"
 
 namespace media {
@@ -16,6 +17,10 @@ bool VideoDecodeAccelerator::CanDecodeOnIOThread() {
   return false;  // not reached
 }
 
+unsigned VideoDecodeAccelerator::GetSurfaceInternalFormat() const {
+  return GL_RGBA;
+}
+
 } // namespace media
 
 namespace base {