1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "base/test/statistics_delta_reader.h" 6 7 #include "base/memory/scoped_ptr.h" 8 #include "base/metrics/histogram.h" 9 #include "base/metrics/histogram_samples.h" 10 #include "testing/gtest/include/gtest/gtest.h" 11 12 namespace base { 13 TEST(StatisticsDeltaReaderTest,Scope)14TEST(StatisticsDeltaReaderTest, Scope) { 15 // Record a histogram before the creation of the recorder. 16 UMA_HISTOGRAM_BOOLEAN("Test", true); 17 18 StatisticsDeltaReader reader; 19 20 // Verify that no histogram is recorded. 21 scoped_ptr<HistogramSamples> samples( 22 reader.GetHistogramSamplesSinceCreation("Test")); 23 EXPECT_FALSE(samples); 24 25 // Record a histogram after the creation of the recorder. 26 UMA_HISTOGRAM_BOOLEAN("Test", true); 27 28 // Verify that one histogram is recorded. 29 samples = reader.GetHistogramSamplesSinceCreation("Test"); 30 EXPECT_TRUE(samples); 31 EXPECT_EQ(1, samples->TotalCount()); 32 } 33 34 } // namespace base 35