cc: Add UniqueNotifier to cc/base.

cc/base/delayed_unique_notifier_unittest.cc

+// Copyright 2014 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 "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
+#include "cc/base/delayed_unique_notifier.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+class DelayedUniqueNotifierTest : public testing::Test {
+ public:
+  DelayedUniqueNotifierTest()
+      : notification_count_(0), expected_notification_count_(0) {}
+
+  virtual void SetUp() OVERRIDE {
+    notification_count_ = 0;
+    expected_notification_count_ = 0;
+    last_notification_time_ = base::TimeTicks();
+  }
+
+  void Notify() {
+    ++notification_count_;
+    last_notification_time_ = base::TimeTicks::Now();
+    if (notification_count_ >= expected_notification_count_)
+      run_loop_->Quit();
+  }
+
+  int NotificationCount() const { return notification_count_; }
+
+  base::TimeTicks LastNotificationTime() const {
+    return last_notification_time_;
+  }
+
+  void RunUntilNotificationCount(int count) {
+    expected_notification_count_ = count;
+    run_loop_.reset(new base::RunLoop);
+    run_loop_->Run();
+
+    // Pump through the remained or messages.

[reveman, 2014/05/27 21:20:24]

nit: I don't understand this comment

[vmpstr, 2014/05/27 21:50:41]

Changed it a bit. The problem is that if we erroneously schedule two runs with 0
delay, then run loop will exit after the first run and the second run would
still be in queue, thus the test would pass when it shouldn't have.

+    base::RunLoop().RunUntilIdle();

[reveman, 2014/05/27 21:20:24]

Why do we need this? I assume run_loop_.reset() doesn't work.

+  }
+
+ protected:
+  int notification_count_;
+  int expected_notification_count_;
+  base::TimeTicks last_notification_time_;
+  scoped_ptr<base::RunLoop> run_loop_;
+};
+
+TEST_F(DelayedUniqueNotifierTest, HalfSecondDelay) {

[reveman, 2014/05/27 21:20:24]

HalfSecondDelay is not accurate anymore

[vmpstr, 2014/05/27 21:50:41]

Oops. Changed.

+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(1);
+  DelayedUniqueNotifier notifier(
+      base::MessageLoopProxy::current(),
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Basic schedule for |delay| from now.
+  base::TimeTicks expected_time = base::TimeTicks::Now() + delay;
+  notifier.Schedule();
+
+  // Expect that we ran only once at least |delay| from now.
+  RunUntilNotificationCount(1);
+  EXPECT_EQ(1, NotificationCount());
+  EXPECT_GE(LastNotificationTime(), expected_time);
+
+  // 5 schedules should result in only one run.
+  for (int i = 0; i < 5; ++i) {
+    expected_time = base::TimeTicks::Now() + delay;
+    notifier.Schedule();
+  }
+
+  RunUntilNotificationCount(2);
+  EXPECT_EQ(2, NotificationCount());
+  EXPECT_GE(LastNotificationTime(), expected_time);
+}
+
+TEST_F(DelayedUniqueNotifierTest, RescheduleDelay) {
+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(1);
+  DelayedUniqueNotifier notifier(
+      base::MessageLoopProxy::current(),
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Schedule constantly for a while.
+  base::TimeTicks expected_time;
+  base::TimeTicks future_time =
+      base::TimeTicks::Now() + base::TimeDelta::FromMilliseconds(1);
+  do {
+    expected_time = base::TimeTicks::Now() + delay;
+    notifier.Schedule();
+  } while (base::TimeTicks::Now() < future_time);
+
+  // Finish running and expect only one run.
+  RunUntilNotificationCount(1);
+  EXPECT_EQ(1, NotificationCount());
+
+  EXPECT_GE(LastNotificationTime(), expected_time);
+}
+
+TEST_F(DelayedUniqueNotifierTest, Cancel) {
+  base::TimeDelta delay = base::TimeDelta::FromInternalValue(1);
+  DelayedUniqueNotifier notifier(
+      base::MessageLoopProxy::current(),
+      base::Bind(&DelayedUniqueNotifierTest::Notify, base::Unretained(this)),
+      delay);
+
+  EXPECT_EQ(0, NotificationCount());
+
+  // Schedule for |delay| seconds from now.
+  notifier.Schedule();
+
+  // Cancel the run.
+  notifier.Cancel();
+
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(0, NotificationCount());
+
+  // Schedule for |delay| seconds from now and let it run.
+  base::TimeTicks expected_time = base::TimeTicks::Now() + delay;
+  notifier.Schedule();
+
+  RunUntilNotificationCount(1);
+  EXPECT_EQ(1, NotificationCount());
+  EXPECT_GE(LastNotificationTime(), expected_time);
+
+  // Schedule for |delay| seconds from now.
+  notifier.Schedule();
+
+  // Cancel the run again.
+  notifier.Cancel();
+
+  base::RunLoop().RunUntilIdle();
+  EXPECT_EQ(1, NotificationCount());
+}

[reveman, 2014/05/27 21:20:24]

nit: blank line here

[vmpstr, 2014/05/27 21:50:41]

Done.

+}  // namespace
+}  // namespace cc