Add VideoPacket struct for video packets. Refactor Decode interface to use it.

remoting/protocol/stream_writer.cc

Index: remoting/protocol/stream_writer.cc
diff --git a/remoting/protocol/stream_writer.cc b/remoting/protocol/stream_writer.cc
index 33a4798ef35a1633e972dc0cddccd036ffb86cb0..9e1ddd4f5f882c80b2e4b77d74bf2dfdcc753540 100644
--- a/remoting/protocol/stream_writer.cc
+++ b/remoting/protocol/stream_writer.cc
@@ -39,7 +39,7 @@ bool EventStreamWriter::SendMessage(const ChromotingClientMessage& message) {
   return buffered_writer_->Write(SerializeAndFrameMessage(message));
 }
 
-bool ControlStreamWriter::SendMessage(const ChromotingHostMessage& message) {
+bool ControlStreamWriter::SendMessage(const ControlMessage& message) {
   return buffered_writer_->Write(SerializeAndFrameMessage(message));
 }