Convert all usages of mojo::ErrorHandler in //device/serial to callbacks.

device/serial/data_receiver.cc

Index: device/serial/data_receiver.cc
diff --git a/device/serial/data_receiver.cc b/device/serial/data_receiver.cc
index 2f238e317d31251155a900b76000b5a7b2cfecb8..82d0153fe287dfcca74b0cdd025e7631c751e9f3 100644
--- a/device/serial/data_receiver.cc
+++ b/device/serial/data_receiver.cc
@@ -117,9 +117,11 @@ DataReceiver::DataReceiver(
       fatal_error_value_(fatal_error_value),
       shut_down_(false),
       weak_factory_(this) {
-  source_.set_error_handler(this);
+  source_.set_connection_error_handler(
+      base::Bind(&DataReceiver::OnConnectionError, base::Unretained(this)));
   source_->Init(buffer_size);
-  client_.set_error_handler(this);
+  client_.set_connection_error_handler(
+      base::Bind(&DataReceiver::OnConnectionError, base::Unretained(this)));
 }
 
 bool DataReceiver::Receive(const ReceiveDataCallback& callback,