media: Followup changes to VideoFrame StructTraits.

media/mojo/interfaces/media_types.mojom

Index: media/mojo/interfaces/media_types.mojom
diff --git a/media/mojo/interfaces/media_types.mojom b/media/mojo/interfaces/media_types.mojom
index e206edbd6d082a8b73832769d2be48655f1a7e9d..5448756c7c511e13472f9804ac0120240b7a874e 100644
--- a/media/mojo/interfaces/media_types.mojom
+++ b/media/mojo/interfaces/media_types.mojom
@@ -213,22 +213,24 @@ struct VideoFrame {
   // Natural size of the frame.
   gfx.mojom.Size natural_size;
 
-  // True if end of stream.
-  bool end_of_stream;
-
   // Timestamp in microseconds of the associated frame.
   mojo.common.mojom.TimeDelta timestamp;
 
-  // Contents of the video frame. Will be null for end of stream frames.
-  VideoFrameData? data;
+  // Contents of the video frame (or EOS marker).
+  VideoFrameData data;
 };
 
 // Possible choices for storing VideoFrame data.
 union VideoFrameData {
+  EosVideoFrameData eos_data;
   SharedBufferVideoFrameData shared_buffer_data;
   MailboxVideoFrameData mailbox_data;
 };
 
+// A marker for EOS frames.
+struct EosVideoFrameData {
+};
+
 // This defines video frame data stored in a Mojo shared buffer.
 struct SharedBufferVideoFrameData {
   // Reference to the shared memory containing the frame's data.