Fix the incorrectly named time points in VisitDatabaseTest.GetHistoryCount.

components/history/core/browser/visit_database_unittest.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 <set>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/strings/string_util.h"
@@ skipping 399 matching lines @@
   // Now try without de-duping, expect to see all visible visits to url id 1.
   options.duplicate_policy = QueryOptions::KEEP_ALL_DUPLICATES;
   GetVisibleVisitsForURL(url_id, options, &results);
   ASSERT_EQ(static_cast<size_t>(3), results.size());
   EXPECT_TRUE(IsVisitInfoEqual(results[0], test_visit_rows[5]));
   EXPECT_TRUE(IsVisitInfoEqual(results[1], test_visit_rows[1]));
   EXPECT_TRUE(IsVisitInfoEqual(results[2], test_visit_rows[0]));
 }
 
 TEST_F(VisitDatabaseTest, GetHistoryCount) {
-  Time today = Time::Now().LocalMidnight();
-  // Find the beginning of yesterday and the day before yesterday. We cannot use
-  // TimeDelta::FromDays(1), as this simply removes 24 hours and thus does not
-  // work correctly with DST shifts. Instead, we'll jump 36 hours (i.e.
-  // somewhere in the middle of the previous day), and use |LocalMidnight()| to
-  // round down to the beginning of the day in the local time, taking timezones
-  // and DST into account. This is necessary to achieve the same equivalence
-  // class on days as the DATE(..., 'localtime') function in SQL.
-  Time yesterday = (today - TimeDelta::FromHours(36)).LocalMidnight();
-  Time two_days_ago = (yesterday - TimeDelta::FromHours(36)).LocalMidnight();
+  // Start with a day in the middle of summer, so that we are nowhere near
+  // DST shifts.
+  Time today;
+  ASSERT_TRUE(Time::FromString("2015-07-07", &today));
+  Time yesterday = today - TimeDelta::FromDays(1);
+  Time two_days_ago = yesterday - TimeDelta::FromDays(1);
   Time now = two_days_ago;
 
   ui::PageTransition standard_transition = ui::PageTransitionFromInt(
       ui::PAGE_TRANSITION_TYPED |
       ui::PAGE_TRANSITION_CHAIN_START |
       ui::PAGE_TRANSITION_CHAIN_END);
 
   // Add 5 visits (3 distinct URLs) for the day before yesterday.
   // Whether the URL was browsed on this machine or synced has no effect.
   VisitRow first_day_1(1, now, 0, standard_transition, 0);
@@ skipping 79 matching lines @@
                               &result));
   EXPECT_EQ(4, result);
 
   // A range that contains no visits will return 0.
   EXPECT_TRUE(GetHistoryCount(two_days_ago + TimeDelta::FromMicroseconds(1),
                               two_days_ago + TimeDelta::FromHours(1),
                               &result));
   EXPECT_EQ(0, result);
 
   // If this timezone uses DST, test the behavior on days when the time
-  // is shifted forward and backward.
+  // is shifted forward and backward. Note that in this case we cannot use
+  // TimeDelta::FromDays(1) to move one day, as this simply removes 24 hours and
+  // thus does not work correctly with DST shifts. Instead, we'll go back
+  // 1 second (i.e. somewhere in the middle of the previous day), and use
+  // |LocalMidnight()| to round down to the beginning of the day in the local
+  // time, taking timezones and DST into account. This is necessary to achieve
+  // the same equivalence class on days as the DATE(..., 'localtime') function
+  // in SQL.
   Time shift_forward;
   Time shift_backward;
   Time current_day = (two_days_ago - TimeDelta::FromSeconds(1)).LocalMidnight();
   for (int i = 0; i < 366; i++) {
     current_day = (current_day - TimeDelta::FromSeconds(1)).LocalMidnight();
     Time after_24_hours = current_day + TimeDelta::FromHours(24);
 
     if (current_day == after_24_hours.LocalMidnight()) {
       // More than 24 hours. Shift backward.
       shift_backward = current_day;
@@ skipping 42 matching lines @@
     AddVisit(&forward_2, SOURCE_BROWSED);
 
     EXPECT_TRUE(GetHistoryCount(shift_forward,
                                 shift_forward + TimeDelta::FromHours(24),
                                 &result));
     EXPECT_EQ(2, result);
   }
 }
 
 }  // namespace history