Remove confusing logic in QuicChromiumClientStream::Read

net/quic/chromium/quic_chromium_client_stream.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/quic/chromium/quic_chromium_client_stream.h"
 
 #include <utility>
 
 #include "base/bind_helpers.h"
 #include "base/callback_helpers.h"
@@ skipping 198 matching lines @@
   if (IsDoneReading())
     return 0;  // EOF
 
   if (!HasBytesToRead())
     return ERR_IO_PENDING;
 
   iovec iov;
   iov.iov_base = buf->data();
   iov.iov_len = buf_len;
   size_t bytes_read = Readv(&iov, 1);
-  // If no more body bytes and trailers are to be delivered, return
-  // ERR_IO_PENDING now because onDataAvailable() will be called after trailers.
-  if (bytes_read == 0 && !FinishedReadingTrailers())
-    return ERR_IO_PENDING;
+  // Since HasBytesToRead is true, Readv() must of read some data.
+  DCHECK_NE(0u, bytes_read);
   return bytes_read;
 }
 
 bool QuicChromiumClientStream::CanWrite(const CompletionCallback& callback) {
   bool can_write = session()->connection()->CanWrite(HAS_RETRANSMITTABLE_DATA);
   if (!can_write) {
     session()->MarkConnectionLevelWriteBlocked(id());
     DCHECK(callback_.is_null());
     callback_ = callback;
   }
@@ skipping 52 matching lines @@
 
 void QuicChromiumClientStream::DisableConnectionMigration() {
   can_migrate_ = false;
 }
 
 bool QuicChromiumClientStream::IsFirstStream() {
   return id() == kHeadersStreamId + 2;
 }
 
 }  // namespace net