Throttle Socket watcher RTT notifications from QUIC

net/nqe/socket_watcher_unittest.cc

+// Copyright 2017 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/nqe/socket_watcher.h"
+
+#include <memory>
+
+#include "base/bind.h"
+#include "base/test/simple_test_tick_clock.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
+#include "net/socket/socket_performance_watcher.h"
+#include "net/socket/socket_performance_watcher_factory.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace net {
+
+namespace nqe {
+
+namespace internal {
+
+namespace {
+
+void OnUpdatedRTTAvailable(SocketPerformanceWatcherFactory::Protocol protocol,
+                           const base::TimeDelta& rtt) {}
+
+// Verify that the buffer size is never exceeded.
+TEST(NetworkQualitySocketWatcherTest, NotificationsThrottled) {
+  SocketWatcher socket_watcher(SocketPerformanceWatcherFactory::PROTOCOL_QUIC,
+                               base::TimeDelta::FromMilliseconds(2000),
+                               base::ThreadTaskRunnerHandle::Get(),
+                               base::Bind(OnUpdatedRTTAvailable));
+
+  std::unique_ptr<base::SimpleTestTickClock> tick_clock(
+      new base::SimpleTestTickClock());
+  base::SimpleTestTickClock* tick_clock_ptr = tick_clock.get();
+  tick_clock_ptr->SetNowTicks(base::TimeTicks::Now());
+
+  socket_watcher.SetTickClockForTesting(std::move(tick_clock));

[RyanSturm, 2017/02/15 17:42:08]

nit: I'd prefer this passed a constructor param, and the factory can pass in the
default tick clock. wdyt?

[tbansal1, 2017/02/15 20:37:42]

Done.

+
+  EXPECT_TRUE(socket_watcher.ShouldNotifyUpdatedRTT());
+  socket_watcher.OnUpdatedRTTAvailable(base::TimeDelta::FromSeconds(10));
+
+  EXPECT_FALSE(socket_watcher.ShouldNotifyUpdatedRTT());
+
+  tick_clock_ptr->Advance(base::TimeDelta::FromMilliseconds(1000));
+  // Minimum interval between consecutive notifications is 2000 msec.
+  EXPECT_FALSE(socket_watcher.ShouldNotifyUpdatedRTT());
+
+  // Advance the clock by 1000 msec more so that the current time is at least
+  // 2000 msec more than the last time |socket_watcher| received a notification.
+  tick_clock_ptr->Advance(base::TimeDelta::FromMilliseconds(1000));
+  EXPECT_TRUE(socket_watcher.ShouldNotifyUpdatedRTT());
+}
+
+}  // namespace
+
+}  // namespace internal
+
+}  // namespace nqe
+
+}  // namespace net