Simplify message parsing.

remoting/protocol/message_serialization.h

Index: remoting/protocol/message_serialization.h
diff --git a/remoting/protocol/message_serialization.h b/remoting/protocol/message_serialization.h
index c550fbeba8c75efeb52056fd6ce77a7fbd5749ee..2a035ff5101e57870d0e448813ef766b136b0029 100644
--- a/remoting/protocol/message_serialization.h
+++ b/remoting/protocol/message_serialization.h
@@ -9,6 +9,7 @@
 #define REMOTING_PROTOCOL_MESSAGE_SERIALIZATION_H_
 
 #include "net/base/io_buffer.h"
+#include "remoting/base/compound_buffer.h"
 
 #if defined(USE_SYSTEM_PROTOBUF)
 #include <google/protobuf/message_lite.h>
@@ -19,6 +20,18 @@
 namespace remoting {
 namespace protocol {
 
+template <class T>
+scoped_ptr<T> ParseMessage(CompoundBuffer* buffer) {
+  scoped_ptr<T> message(new T());
+  CompoundBufferInputStream stream(buffer);
+  if (!message->ParseFromZeroCopyStream(&stream)) {
+    LOG(WARNING) << "Received message that is not a valid protocol buffer.";
+    return nullptr;
+  }
+  DCHECK_EQ(stream.position(), buffer->total_bytes());
+  return message;
+}
+
 // Serialize the Protocol Buffer message and provide sufficient framing for
 // sending it over the wire.
 // This will provide sufficient prefix and suffix for the receiver side to