Simplify VideoEncoder interface.

remoting/protocol/protobuf_video_writer.cc

Index: remoting/protocol/protobuf_video_writer.cc
diff --git a/remoting/protocol/protobuf_video_writer.cc b/remoting/protocol/protobuf_video_writer.cc
index 08e937b571ad329f834175a3e752b146f3beec89..7fd57c7bca42ca27564f930110749dfbfe12c763 100644
--- a/remoting/protocol/protobuf_video_writer.cc
+++ b/remoting/protocol/protobuf_video_writer.cc
@@ -63,6 +63,11 @@ bool ProtobufVideoWriter::is_connected() {
 
 void ProtobufVideoWriter::ProcessVideoPacket(scoped_ptr<VideoPacket> packet,
                                              const base::Closure& done) {
+  // Older clients may expect deprecated flags field. Always set it to 7.
+  //
+  // TODO(sergeyu): Remove this field after M31 is released.
+  packet->set_deprecated_flags(7);
+
   buffered_writer_.Write(SerializeAndFrameMessage(*packet), done);
 }