Make PacketReader/PacketWriter interfaces async-only.

blimp/net/stream_packet_writer.cc

Index: blimp/net/stream_packet_writer.cc
diff --git a/blimp/net/stream_packet_writer.cc b/blimp/net/stream_packet_writer.cc
index 221cdd170e7fa87eb5b0f31742de8e8b9591f4f8..2d4ee0a2f21c6c6ddddd0066fa58f606a8b85c35 100644
--- a/blimp/net/stream_packet_writer.cc
+++ b/blimp/net/stream_packet_writer.cc
@@ -47,14 +47,15 @@ StreamPacketWriter::StreamPacketWriter(net::StreamSocket* socket)
 
 StreamPacketWriter::~StreamPacketWriter() {}
 
-int StreamPacketWriter::WritePacket(scoped_refptr<net::DrainableIOBuffer> data,
-                                    const net::CompletionCallback& callback) {
+void StreamPacketWriter::WritePacket(scoped_refptr<net::DrainableIOBuffer> data,
+                                     const net::CompletionCallback& callback) {
   DCHECK_EQ(WriteState::IDLE, write_state_);
   DCHECK(data);
   if (data->BytesRemaining() == 0) {
     // The packet is empty; your argument is invalid.
     DLOG(ERROR) << "Attempted to write zero-length packet.";
-    return net::ERR_INVALID_ARGUMENT;
+    base::MessageLoop::current()->PostTask(
+        FROM_HERE, base::Bind(callback, net::ERR_INVALID_ARGUMENT));
   }
 
   write_state_ = WriteState::HEADER;
@@ -65,16 +66,16 @@ int StreamPacketWriter::WritePacket(scoped_refptr<net::DrainableIOBuffer> data,
 
   int result = DoWriteLoop(false);

[Wez, 2015/11/20 23:42:13]

Why are we passing DoWriteLoop a bool here, when it takes an int?

[Kevin M, 2015/11/24 21:34:36]

Done.

   if (result == net::ERR_IO_PENDING) {
-    // Store the completion callback to invoke when DoWriteLoop completes
-    // asynchronously.
-    callback_ = callback;
-  } else {
     // Release the payload buffer, since the write operation has completed
     // synchronously.

[Wez, 2015/11/20 23:42:13]

Not according to the result test above, it hasn't.

Does this actually pass the unit-tests - if so then we need a new one to trap
this error!

[Kevin M, 2015/11/24 21:34:36]

Done. I must've been interrupted mid-CL, because this portion wasn't done fully.

     payload_buffer_ = nullptr;
-  }
 
-  return result;
+    // Adapt synchronous completion to an asynchronous style.
+    base::MessageLoop::current()->PostTask(FROM_HERE,
+                                           base::Bind(callback, result));
+  } else {
+    callback_ = callback;
+  }
 }
 
 int StreamPacketWriter::DoWriteLoop(int result) {