Remove Client= from device/serial/data_stream.mojom.

device/serial/data_stream_serialization.mojom

Index: device/serial/data_stream_serialization.mojom
diff --git a/device/serial/data_stream_serialization.mojom b/device/serial/data_stream_serialization.mojom
index 259be286061fdf1be02b4c0ba80387deed0d34e9..3112dd5b227b400c084eada1260d12cb9c371949 100644
--- a/device/serial/data_stream_serialization.mojom
+++ b/device/serial/data_stream_serialization.mojom
@@ -13,9 +13,6 @@ struct SerializedDataSender {
 
   // The error to report for sends in progress when a fatal error occurs.
   int32 fatal_error_value;
-
-  // The size of the send buffer.
-  uint32 buffer_size;
 };
 
 // A pending receive error.
@@ -32,6 +29,8 @@ struct SerializedDataReceiver {
   // The control channel to the DataSource from which this DataReceiver receives
   // data.
   DataSource source;
+  // DataSourceClient&
+  handle<message_pipe> source_client;
 
   // The error to report for a receive in progress when a fatal error occurs.
   int32 fatal_error_value;