Change data pipe wrappers used by SerialConnection to use message pipe.

device/serial/data_sender.h

Index: device/serial/data_sender.h
diff --git a/device/serial/data_sender.h b/device/serial/data_sender.h
index 6e5c89e85c0b587643b31f4fc006032844222729..371236fb39320a82c98ab0cdcd07bc388bc6ce05 100644
--- a/device/serial/data_sender.h
+++ b/device/serial/data_sender.h
@@ -16,8 +16,6 @@
 
 namespace device {
 
-class AsyncWaiter;
-
 // A DataSender sends data to a DataSink.
 class DataSender : public serial::DataSinkClient, public mojo::ErrorHandler {
  public:
@@ -26,9 +24,8 @@ class DataSender : public serial::DataSinkClient, public mojo::ErrorHandler {
       SendErrorCallback;
   typedef base::Callback<void()> CancelCallback;
 
-  // Constructs a DataSender to send data to |sink|, using a data pipe with a
-  // buffer size of |buffer_size|, with connection errors reported as
-  // |fatal_error_value|.
+  // Constructs a DataSender to send data to |sink|, using a buffer size of
+  // |buffer_size|, with connection errors reported as |fatal_error_value|.
   DataSender(mojo::InterfacePtr<serial::DataSink> sink,
              uint32_t buffer_size,
              int32_t fatal_error_value);
@@ -57,19 +54,17 @@ class DataSender : public serial::DataSinkClient, public mojo::ErrorHandler {
   virtual void ReportBytesSentAndError(
       uint32_t bytes_sent,
       int32_t error,
-      const mojo::Callback<void(uint32_t)>& callback) override;
+      const mojo::Callback<void()>& callback) override;
 
   // mojo::ErrorHandler override.
   virtual void OnConnectionError() override;
 
-  // Copies data from |pending_sends_| into the data pipe and starts |waiter_|
-  // waiting if the pipe is full. When a PendingSend in |pending_sends_| has
-  // been fully copied into the data pipe, it moves to |sends_awaiting_ack_|.
+  // Sends up to |available_buffer_capacity_| bytes of data from
+  // |pending_sends_| to |sink_|. When a PendingSend in |pending_sends_| has
+  // been fully copied transmitted to |sink_|, it moves to
+  // |sends_awaiting_ack_|.
   void SendInternal();
 
-  // Invoked when |handle_| is ready for writes. Calls SendInternal().
-  void OnDoneWaiting(MojoResult result);
-
   // Dispatches a cancel callback if one is pending.
   void RunCancelCallback();
 
@@ -80,27 +75,23 @@ class DataSender : public serial::DataSinkClient, public mojo::ErrorHandler {
   // The control connection to the data sink.
   mojo::InterfacePtr<serial::DataSink> sink_;
 
-  // The data connection to the data sink.
-  mojo::ScopedDataPipeProducerHandle handle_;
-
   // The error value to report in the event of a fatal error.
   const int32_t fatal_error_value_;
 
-  // A waiter used to wait until |handle_| is writable if we are waiting.
-  scoped_ptr<AsyncWaiter> waiter_;
-
-  // A queue of PendingSend that have not yet been fully written to the data
-  // pipe.
+  // A queue of PendingSend that have not yet been fully sent to |sink_|.
   std::queue<linked_ptr<PendingSend> > pending_sends_;
 
-  // A queue of PendingSend that have been written to the data pipe, but have
-  // not yet been acked by the DataSink.
+  // A queue of PendingSend that have been sent to |sink_|, but have not yet
+  // been acked by the DataSink.
   std::queue<linked_ptr<PendingSend> > sends_awaiting_ack_;
 
   // The callback to report cancel completion if a cancel operation is in
   // progress.
   CancelCallback pending_cancel_;
 
+  // The number of bytes available for buffering in the DataSink.
+  uint32_t available_buffer_capacity_;
+
   // Whether we have encountered a fatal error and shut down.
   bool shut_down_;