Makes the BattOrConnection read messages instead of bytes

tools/battor_agent/battor_agent.cc

Index: tools/battor_agent/battor_agent.cc
diff --git a/tools/battor_agent/battor_agent.cc b/tools/battor_agent/battor_agent.cc
index 65289a63ad50b7ef76981d78c265180b9936e170..7dfbfce9d7835a7a0c70023e6b2db26340b5c11a 100644
--- a/tools/battor_agent/battor_agent.cc
+++ b/tools/battor_agent/battor_agent.cc
@@ -114,9 +114,9 @@ void BattOrAgent::OnBytesSent(bool success) {
   }
 }
 
-void BattOrAgent::OnBytesRead(bool success,
-                              BattOrMessageType type,
-                              scoped_ptr<vector<char>> bytes) {
+void BattOrAgent::OnMessageRead(bool success,
+                                BattOrMessageType type,
+                                scoped_ptr<vector<char>> bytes) {
   if (!success) {
     CompleteCommand(BATTOR_ERROR_RECEIVE_ERROR);
     return;
@@ -182,7 +182,7 @@ void BattOrAgent::PerformAction(Action action) {
       SendControlMessage(BATTOR_CONTROL_MESSAGE_TYPE_INIT, 0, 0);
       break;
     case Action::READ_INIT_ACK:
-      connection_->ReadBytes(sizeof(BattOrControlMessageAck));
+      connection_->ReadMessage(sizeof(BattOrControlMessageAck));

[nednguyen, 2016/01/06 22:03:13]

Can yo abstract this to ReadMessage(message_type), and ReadMessage knows how to
compute the message size depending on the message type?
This way, call site do not have to worry about the detail of 
max_data_bytes_to_read not including any start, end, or escape bytes.

[charliea (OOO until 10-5), 2016/01/07 16:00:12]

I like this idea a lot. Done.

       break;
     case Action::SEND_SET_GAIN:
       // Set the BattOr's gain. Setting the gain tells the BattOr the range of
@@ -191,13 +191,13 @@ void BattOrAgent::PerformAction(Action action) {
                          0);
       break;
     case Action::READ_SET_GAIN_ACK:
-      connection_->ReadBytes(sizeof(BattOrControlMessageAck));
+      connection_->ReadMessage(sizeof(BattOrControlMessageAck));
       break;
     case Action::SEND_START_TRACING:
       SendControlMessage(BATTOR_CONTROL_MESSAGE_TYPE_START_SAMPLING_SD, 0, 0);
       break;
     case Action::READ_START_TRACING_ACK:
-      connection_->ReadBytes(sizeof(BattOrControlMessageAck));
+      connection_->ReadMessage(sizeof(BattOrControlMessageAck));
       break;
     case Action::INVALID:
       NOTREACHED();