Throttle Socket watcher RTT notifications from QUIC

net/socket/tcp_socket_posix.cc

Index: net/socket/tcp_socket_posix.cc
diff --git a/net/socket/tcp_socket_posix.cc b/net/socket/tcp_socket_posix.cc
index 1e4f6eddf68e8c4b10adf0d1d3c3bd8e0caebb1b..438d5aab41140a27ddf2cff6853c6253738a1be2 100644
--- a/net/socket/tcp_socket_posix.cc
+++ b/net/socket/tcp_socket_posix.cc
@@ -15,7 +15,7 @@
 #include "base/metrics/histogram_macros.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/task_scheduler/post_task.h"
-#include "base/time/default_tick_clock.h"
+#include "base/time/time.h"
 #include "net/base/address_list.h"
 #include "net/base/io_buffer.h"
 #include "net/base/ip_endpoint.h"
@@ -144,8 +144,6 @@ TCPSocketPosix::TCPSocketPosix(
     NetLog* net_log,
     const NetLogSource& source)
     : socket_performance_watcher_(std::move(socket_performance_watcher)),
-      tick_clock_(new base::DefaultTickClock()),
-      rtt_notifications_minimum_interval_(base::TimeDelta::FromSeconds(1)),
       use_tcp_fastopen_(false),
       tcp_fastopen_write_attempted_(false),
       tcp_fastopen_connected_(false),
@@ -483,11 +481,6 @@ void TCPSocketPosix::EndLoggingMultipleConnectAttempts(int net_error) {
   }
 }
 
-void TCPSocketPosix::SetTickClockForTesting(
-    std::unique_ptr<base::TickClock> tick_clock) {
-  tick_clock_ = std::move(tick_clock);
-}
-
 void TCPSocketPosix::AcceptCompleted(
     std::unique_ptr<TCPSocketPosix>* tcp_socket,
     IPEndPoint* address,
@@ -723,13 +716,6 @@ int TCPSocketPosix::TcpFastOpenWrite(IOBuffer* buf,
 
 void TCPSocketPosix::NotifySocketPerformanceWatcher() {
 #if defined(TCP_INFO)
-  const base::TimeTicks now_ticks = tick_clock_->NowTicks();
-  // Do not notify |socket_performance_watcher_| if the last notification was
-  // recent than |rtt_notifications_minimum_interval_| ago. This helps in
-  // reducing the overall overhead of the tcp_info syscalls.
-  if (now_ticks - last_rtt_notification_ < rtt_notifications_minimum_interval_)
-    return;
-

[Ryan Hamilton, 2017/02/15 23:08:17]

This is a nice cleanup.

Should we do something similar for TCPSocketWin?

[tbansal1, 2017/02/15 23:16:12]

TCPSocketWin currently does not push any RTT readings. I guess I need to read up
on Windows APIs to write that code. There is also a TODO from bmcquade here:
https://cs.chromium.org/chromium/src/net/socket/tcp_socket_win.cc?rcl=32e074e...
So, I may be I can copy his code once he implements that :)

[Ryan Hamilton, 2017/02/16 00:01:42]

Since windows is huge part of Chrome's user base, it would be good to make sure
we do this. Can you follow up with bcmquade to ensure that this is done by
someone?

[tbansal1, 2017/02/16 00:10:58]

Filed https://bugs.chromium.org/p/chromium/issues/detail?id=692825.

   // Check if |socket_performance_watcher_| is interested in receiving a RTT
   // update notification.
   if (!socket_performance_watcher_ ||
@@ -751,7 +737,6 @@ void TCPSocketPosix::NotifySocketPerformanceWatcher() {
 
   socket_performance_watcher_->OnUpdatedRTTAvailable(
       base::TimeDelta::FromMicroseconds(info.tcpi_rtt));
-  last_rtt_notification_ = now_ticks;
 #endif  // defined(TCP_INFO)
 }