Remove unused ability to disable flow control in QUIC

net/quic/reliable_quic_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/reliable_quic_stream.h"
 
 #include "base/logging.h"
 #include "base/profiler/scoped_tracker.h"
 #include "net/quic/iovector.h"
 #include "net/quic/quic_flow_controller.h"
@@ skipping 330 matching lines @@
     DLOG(ERROR) << ENDPOINT << "Attempt to write when the write side is closed";
     return QuicConsumedData(0, false);
   }
 
   // How much data we want to write.
   size_t write_length = TotalIovecLength(iov, iov_count);
 
   // A FIN with zero data payload should not be flow control blocked.
   bool fin_with_zero_data = (fin && write_length == 0);
 
-  if (flow_controller_.IsEnabled()) {
-    // How much data we are allowed to write from flow control.
-    QuicByteCount send_window = flow_controller_.SendWindowSize();
-    if (stream_contributes_to_connection_flow_control_) {
-      send_window =
-          min(send_window, connection_flow_controller_->SendWindowSize());
-    }
+  // How much data we are allowed to write from flow control.
+  QuicByteCount send_window = flow_controller_.SendWindowSize();
+  if (stream_contributes_to_connection_flow_control_) {
+    send_window =
+        min(send_window, connection_flow_controller_->SendWindowSize());
+  }
 
-    if (send_window == 0 && !fin_with_zero_data) {
-      // Quick return if we can't send anything.
-      MaybeSendBlocked();
-      return QuicConsumedData(0, false);
-    }
+  if (send_window == 0 && !fin_with_zero_data) {
+    // Quick return if we can't send anything.
+    MaybeSendBlocked();
+    return QuicConsumedData(0, false);
+  }
 
-    if (write_length > send_window) {
-      // Don't send the FIN if we aren't going to send all the data.
-      fin = false;
+  if (write_length > send_window) {
+    // Don't send the FIN if we aren't going to send all the data.
+    fin = false;
 
-      // Writing more data would be a violation of flow control.
-      write_length = static_cast<size_t>(send_window);
-    }
+    // Writing more data would be a violation of flow control.
+    write_length = static_cast<size_t>(send_window);
   }
 
   // Fill an IOVector with bytes from the iovec.
   IOVector data;
   data.AppendIovecAtMostBytes(iov, iov_count, write_length);
 
   QuicConsumedData consumed_data = session()->WritevData(
       id(), data, stream_bytes_written_, fin, GetFecProtection(),
       ack_notifier_delegate);
   stream_bytes_written_ += consumed_data.bytes_consumed;
@@ skipping 69 matching lines @@
   // endpoints have the same connection level flow control state, mark all
   // unreceived or buffered bytes as consumed.
   QuicByteCount bytes_to_consume =
       flow_controller_.highest_received_byte_offset() -
       flow_controller_.bytes_consumed();
   AddBytesConsumed(bytes_to_consume);
 }
 
 void ReliableQuicStream::OnWindowUpdateFrame(
     const QuicWindowUpdateFrame& frame) {
-  if (!flow_controller_.IsEnabled()) {
-    DLOG(DFATAL) << "Flow control not enabled! " << version();
-    return;
-  }
   if (flow_controller_.UpdateSendWindowOffset(frame.byte_offset)) {
     // We can write again!
     // TODO(rjshade): This does not respect priorities (e.g. multiple
     //                outstanding POSTs are unblocked on arrival of
     //                SHLO with initial window).
     // As long as the connection is not flow control blocked, we can write!
     OnCanWrite();
   }
 }
 
 bool ReliableQuicStream::MaybeIncreaseHighestReceivedOffset(
     QuicStreamOffset new_offset) {
-  if (!flow_controller_.IsEnabled()) {
-    return false;
-  }
   uint64 increment =
       new_offset - flow_controller_.highest_received_byte_offset();
   if (!flow_controller_.UpdateHighestReceivedOffset(new_offset)) {
     return false;
   }
 
   // If |new_offset| increased the stream flow controller's highest received
   // offset, then we need to increase the connection flow controller's value
   // by the incremental difference.
   if (stream_contributes_to_connection_flow_control_) {
     connection_flow_controller_->UpdateHighestReceivedOffset(
         connection_flow_controller_->highest_received_byte_offset() +
         increment);
   }
   return true;
 }
 
 void ReliableQuicStream::AddBytesSent(QuicByteCount bytes) {
-  if (flow_controller_.IsEnabled()) {
-    flow_controller_.AddBytesSent(bytes);
-    if (stream_contributes_to_connection_flow_control_) {
-      connection_flow_controller_->AddBytesSent(bytes);
-    }
+  flow_controller_.AddBytesSent(bytes);
+  if (stream_contributes_to_connection_flow_control_) {
+    connection_flow_controller_->AddBytesSent(bytes);
   }
 }
 
 void ReliableQuicStream::AddBytesConsumed(QuicByteCount bytes) {
-  if (flow_controller_.IsEnabled()) {
-    // Only adjust stream level flow controller if we are still reading.
-    if (!read_side_closed_) {
-      flow_controller_.AddBytesConsumed(bytes);
-    }
+  // Only adjust stream level flow controller if we are still reading.
+  if (!read_side_closed_) {
+    flow_controller_.AddBytesConsumed(bytes);
+  }
 
-    if (stream_contributes_to_connection_flow_control_) {
-      connection_flow_controller_->AddBytesConsumed(bytes);
-    }
+  if (stream_contributes_to_connection_flow_control_) {
+    connection_flow_controller_->AddBytesConsumed(bytes);
   }
 }
 
 void ReliableQuicStream::UpdateSendWindowOffset(QuicStreamOffset new_window) {
   if (flow_controller_.UpdateSendWindowOffset(new_window)) {
     OnCanWrite();
   }
 }
 
 bool ReliableQuicStream::IsFlowControlBlocked() {
   if (flow_controller_.IsBlocked()) {
     return true;
   }
   return stream_contributes_to_connection_flow_control_ &&
       connection_flow_controller_->IsBlocked();
 }
 
 }  // namespace net