Decrease keep-alive period for the video channel to 200ms.

remoting/host/video_scheduler.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 "remoting/host/video_scheduler.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 13 matching lines @@
 #include "third_party/webrtc/modules/desktop_capture/mouse_cursor_shape.h"
 #include "third_party/webrtc/modules/desktop_capture/screen_capturer.h"
 
 namespace remoting {
 
 // Maximum number of frames that can be processed simultaneously.
 // TODO(hclam): Move this value to CaptureScheduler.
 static const int kMaxPendingFrames = 2;
 
 // Interval between empty keep-alive frames. These frames are sent only
-// when there are no real video frames being sent.
-static const int kKeepAlivePacketIntervalMs = 500;
+// when there are no real video frames being sent. To prevent PseudoTCP from
+// resetting congestion window this value must be smaller that then the minimum
+// RTO used in PseudoTCP, which is 250ms.
+static const int kKeepAlivePacketIntervalMs = 200;
 
 VideoScheduler::VideoScheduler(
     scoped_refptr<base::SingleThreadTaskRunner> capture_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> encode_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> network_task_runner,
     scoped_ptr<webrtc::ScreenCapturer> capturer,
     scoped_ptr<VideoEncoder> encoder,
     protocol::CursorShapeStub* cursor_stub,
     protocol::VideoStub* video_stub)
     : capture_task_runner_(capture_task_runner),
@@ skipping 306 matching lines @@
   frame.reset();
 
   scheduler_.RecordEncodeTime(
       base::TimeDelta::FromMilliseconds(packet->encode_time_ms()));
   network_task_runner_->PostTask(
       FROM_HERE, base::Bind(&VideoScheduler::SendVideoPacket, this,
                             base::Passed(&packet)));
 }
 
 }  // namespace remoting