remoting: Extract the utility to get the BytesPerPixel from PixelFormat into a function.

remoting/base/protocol_util.h

Index: remoting/base/protocol_util.h
diff --git a/remoting/base/protocol_util.h b/remoting/base/protocol_util.h
index 16781eb2cede43cc8f3fdee43427d22fe6326e00..94cdc2f0949f03a46dab4bde122c6e73b6eb292e 100644
--- a/remoting/base/protocol_util.h
+++ b/remoting/base/protocol_util.h
@@ -7,6 +7,7 @@
 
 #include "google/protobuf/message_lite.h"
 #include "media/base/data_buffer.h"
+#include "remoting/base/protocol/chromotocol.pb.h"
 
 // This file defines utility methods used for encoding and decoding the protocol
 // used in Chromoting.
@@ -19,6 +20,8 @@ namespace remoting {
 scoped_refptr<media::DataBuffer> SerializeAndFrameMessage(
     const google::protobuf::MessageLite& msg);
 
+int GetBytesPerPixel(PixelFormat format);
+
 }  // namespace remoting
 
 #endif  // REMOTING_BASE_PROTOCOL_UTIL_H_