Assert event timestamp to be monotonic and not from future

third_party/WebKit/Source/platform/HistogramTest.cpp

 // Copyright 2016 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 "platform/Histogram.h"
 
 #include "base/metrics/histogram_samples.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace blink {
 
 class ScopedUsHistogramTimerTest : public ::testing::Test {
 public:
     static void advanceClock(double microseconds)
     {
         s_timeElapsed += microseconds;
     }
 
 protected:
     static double returnMockTime()
     {
         return s_timeElapsed;
     }
 
     virtual void SetUp()
     {
         s_timeElapsed = 0.0;
-        m_originalTimeFunction = setTimeFunctionsForTesting(returnMockTime);
+        m_originalMonotonicTimeFunction = setMonotonicallyIncreasingTimeFunctionForTesting(returnMockTime);
+        m_originalCurrentTimeFunction = setCurrentTimeFunctionForTesting(returnMockTime);
     }
 
     virtual void TearDown()
     {
-        setTimeFunctionsForTesting(m_originalTimeFunction);
+        setMonotonicallyIncreasingTimeFunctionForTesting(m_originalMonotonicTimeFunction);
+        setCurrentTimeFunctionForTesting(m_originalCurrentTimeFunction);
     }
 
 private:
     static double s_timeElapsed;
-    TimeFunction m_originalTimeFunction;
+    TimeFunction m_originalMonotonicTimeFunction;
+    TimeFunction m_originalCurrentTimeFunction;
 };
 
 double ScopedUsHistogramTimerTest::s_timeElapsed;
 
 class TestCustomCountHistogram : public CustomCountHistogram {
 public:
     TestCustomCountHistogram(const char* name, base::HistogramBase::Sample min, base::HistogramBase::Sample max, int32_t bucketCount)
     : CustomCountHistogram(name, min, max, bucketCount) {}
 
     base::HistogramBase* histogram() { return m_histogram; }
 };
 
 TEST_F(ScopedUsHistogramTimerTest, Basic)
 {
     TestCustomCountHistogram scopedUsCounter("test", 0, 10000000, 50);
     {
         ScopedUsHistogramTimer timer(scopedUsCounter);
         advanceClock(0.5);
     }
     // 0.5s == 500000us
     EXPECT_EQ(500000, scopedUsCounter.histogram()->SnapshotSamples()->sum());
 }
 
 } // namespace blink