Add a mechanism for collecting Rappor samples on a daily interval.

components/metrics/daily_interval_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 "components/metrics/daily_interval.h"
+
+#include "base/prefs/testing_pref_service.h"
+#include "components/metrics/daily_observer.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace metrics {
+
+namespace {
+
+const char kTestPrefName[] = "TestPref";
+
+class TestDailyObserver : public DailyObserver {
+ public:
+  TestDailyObserver() : fired_(false) {}
+
+  bool fired() const { return fired_; }
+
+  virtual void OnDailyInterval() OVERRIDE {
+    fired_ = true;
+  };

[Alexei Svitkine (slow), 2014/09/08 15:34:20]

Nit: Unnecessary semicolon. Also, below.

[Steven Holte, 2014/09/12 21:23:31]

Done.

+
+  void Reset() {
+    fired_ = false;
+  };
+
+ private:
+  // True if this event has been observed.
+  bool fired_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestDailyObserver);
+};
+
+class DailyIntervalTest : public testing::Test {
+ public:
+  DailyIntervalTest() : interval_(&prefs_, kTestPrefName) {
+    DailyInterval::RegisterPref(prefs_.registry(), kTestPrefName);
+    interval_.AddObserver(&observer_);
+  }
+
+ protected:
+  TestingPrefServiceSimple prefs_;
+  TestDailyObserver observer_;
+  DailyInterval interval_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(DailyIntervalTest);
+};
+
+}  // namespace
+
+// The event should fire if the preference is not available.
+TEST_F(DailyIntervalTest, TestNewFires) {
+  interval_.CheckInterval();
+  EXPECT_TRUE(observer_.fired());
+}
+
+// The event should fire if the preference is more than a day old.
+TEST_F(DailyIntervalTest, TestOldFires) {
+  base::Time last_time = base::Time::Now() - base::TimeDelta::FromDays(2);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  interval_.CheckInterval();
+  EXPECT_TRUE(observer_.fired());
+}
+
+// The event should fire if the preference is more than a day in the future.
+TEST_F(DailyIntervalTest, TestFutureFires) {
+  base::Time last_time = base::Time::Now() + base::TimeDelta::FromDays(2);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  interval_.CheckInterval();
+  EXPECT_TRUE(observer_.fired());
+}
+
+// The event should not fire if the preference is more recent than a day.
+TEST_F(DailyIntervalTest, TestRecentNotFired) {
+  base::Time last_time = base::Time::Now() - base::TimeDelta::FromMinutes(2);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  interval_.CheckInterval();
+  EXPECT_FALSE(observer_.fired());
+}
+
+// The event should not fire if the preference is less than a day in the future.
+TEST_F(DailyIntervalTest, TestSoonNotFired) {
+  base::Time last_time = base::Time::Now() + base::TimeDelta::FromMinutes(2);
+  prefs_.SetInt64(kTestPrefName, last_time.ToInternalValue());
+  interval_.CheckInterval();
+  EXPECT_FALSE(observer_.fired());
+}
+
+}  // namespace metrics