diff options
Diffstat (limited to 'chromium/ui/latency/average_lag_tracker_unittest.cc')
| -rw-r--r-- | chromium/ui/latency/average_lag_tracker_unittest.cc | 540 |
1 files changed, 0 insertions, 540 deletions
diff --git a/chromium/ui/latency/average_lag_tracker_unittest.cc b/chromium/ui/latency/average_lag_tracker_unittest.cc deleted file mode 100644 index e2a0f223e60..00000000000 --- a/chromium/ui/latency/average_lag_tracker_unittest.cc +++ /dev/null @@ -1,540 +0,0 @@ -// Copyright 2019 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 "ui/latency/average_lag_tracker.h" - -#include "base/test/metrics/histogram_tester.h" -#include "testing/gmock/include/gmock/gmock.h" -#include "testing/gtest/include/gtest/gtest.h" - -using base::Bucket; -using testing::ElementsAre; - -namespace ui { -namespace { - -class AverageLagTrackerTest : public testing::Test { - public: - AverageLagTrackerTest() { ResetHistograms(); } - - void ResetHistograms() { - histogram_tester_ = std::make_unique<base::HistogramTester>(); - } - - const base::HistogramTester& histogram_tester() { return *histogram_tester_; } - - void SetUp() override { - average_lag_tracker_ = std::make_unique<AverageLagTracker>(); - } - - void SyntheticTouchScrollBeginLatencyInfo(base::TimeTicks event_time, - base::TimeTicks frame_time, - float delta, - float predicted_delta = 0) { - ui::LatencyInfo touch_latency(ui::SourceEventType::TOUCH); - touch_latency.set_scroll_update_delta(delta); - touch_latency.set_predicted_scroll_update_delta( - predicted_delta != 0 ? predicted_delta : delta); - - touch_latency.AddLatencyNumberWithTimestamp( - ui::INPUT_EVENT_LATENCY_FIRST_SCROLL_UPDATE_ORIGINAL_COMPONENT, - event_time); - touch_latency.AddLatencyNumberWithTimestamp( - ui::INPUT_EVENT_LATENCY_SCROLL_UPDATE_LAST_EVENT_COMPONENT, event_time); - average_lag_tracker_->AddLatencyInFrame(touch_latency, frame_time, - "ScrollBegin"); - } - - void SyntheticTouchScrollUpdateLatencyInfo(base::TimeTicks event_time, - base::TimeTicks frame_time, - float delta, - float predicted_delta = 0) { - ui::LatencyInfo touch_latency(ui::SourceEventType::TOUCH); - touch_latency.set_scroll_update_delta(delta); - touch_latency.set_predicted_scroll_update_delta( - predicted_delta != 0 ? predicted_delta : delta); - touch_latency.AddLatencyNumberWithTimestamp( - ui::INPUT_EVENT_LATENCY_SCROLL_UPDATE_ORIGINAL_COMPONENT, event_time); - touch_latency.AddLatencyNumberWithTimestamp( - ui::INPUT_EVENT_LATENCY_SCROLL_UPDATE_LAST_EVENT_COMPONENT, event_time); - average_lag_tracker_->AddLatencyInFrame(touch_latency, frame_time, - "ScrollUpdate"); - } - - protected: - std::unique_ptr<AverageLagTracker> average_lag_tracker_; - - std::unique_ptr<base::HistogramTester> histogram_tester_; -}; - -base::TimeTicks MillisecondsToTimeTicks(float t_ms) { - return base::TimeTicks() + base::TimeDelta::FromMilliseconds(t_ms); -} - -// Simulate a simple situation that events at every 10ms and start at t=15ms, -// frame swaps at every 10ms too and start at t=20ms and test we record one -// UMA for ScrollUpdate in one second. -TEST_F(AverageLagTrackerTest, OneSecondInterval) { - base::TimeTicks event_time = - base::TimeTicks() + base::TimeDelta::FromMilliseconds(5); - base::TimeTicks frame_time = - base::TimeTicks() + base::TimeDelta::FromMilliseconds(10); - float scroll_delta = 10; - - // ScrollBegin - event_time += base::TimeDelta::FromMilliseconds(10); // 15ms - frame_time += base::TimeDelta::FromMilliseconds(10); // 20ms - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, scroll_delta); - - // Send 101 ScrollUpdate events to verify that there is 1 AverageLag record - // per 1 second. - const int kUpdates = 101; - for (int i = 0; i < kUpdates; i++) { - event_time += base::TimeDelta::FromMilliseconds(10); - frame_time += base::TimeDelta::FromMilliseconds(10); - // First 50 has positive delta, others negetive delta. - const int sign = (i < kUpdates / 2) ? 1 : -1; - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - sign * scroll_delta); - } - - // ScrollBegin report_time is at 20ms, so the next ScrollUpdate report_time is - // at 1020ms. The last event_time that finish this report should be later than - // 1020ms. - EXPECT_EQ(event_time, - base::TimeTicks() + base::TimeDelta::FromMilliseconds(1025)); - EXPECT_EQ(frame_time, - base::TimeTicks() + base::TimeDelta::FromMilliseconds(1030)); - - // ScrollBegin AverageLag are the area between the event original component - // (time=15ms, delta=10px) to the frame swap time (time=20ms, expect finger - // position at delta=15px). The AverageLag scaled to 1 second is - // (0.5*(10px+15px)*5ms)/5ms = 12.5px. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(12, 1))); - // This ScrollUpdate AverageLag are calculated as the finger uniformly scroll - // 10px each frame. For scroll up/down frame, the Lag at the last frame swap - // is 5px, and Lag at this frame swap is 15px. For the one changing direction, - // the Lag is from 5 to 10 and down to 5 again. So total LagArea is 99 * 100, - // plus 75. the AverageLag in 1 second is 9.975px. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(9, 1))); - EXPECT_THAT( - histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive"), - ElementsAre(Bucket(0, 1))); - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative", 0); - ResetHistograms(); - - // Send another ScrollBegin to end the unfinished ScrollUpdate report. - event_time += base::TimeDelta::FromMilliseconds(10); - frame_time += base::TimeDelta::FromMilliseconds(10); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, scroll_delta); - - // The last ScrollUpdate's lag is 8.75px and truncated to 8. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(8, 1))); - EXPECT_THAT( - histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive"), - ElementsAre(Bucket(0, 1))); - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative", 0); -} - -// Test the case that event's frame swap time is later than next event's -// creation time. (i.e, event at t=10ms will be dispatch at t=30ms, while next -// event is at t=20ms). -TEST_F(AverageLagTrackerTest, LargerLatency) { - base::TimeTicks event_time = MillisecondsToTimeTicks(10); - base::TimeTicks frame_time = - event_time + base::TimeDelta::FromMilliseconds(20); - float scroll_delta = 10; - - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, scroll_delta); - - // Send 2 ScrollUpdate. The second one will record AverageLag.ScrollBegin as - // it's event_time is larger or equal to ScrollBegin's frame_time. - for (int i = 0; i < 2; i++) { - event_time += base::TimeDelta::FromMilliseconds(10); - frame_time = event_time + base::TimeDelta::FromMilliseconds(20); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, scroll_delta); - } - - // ScrollBegin AveragLag are from t=10ms to t=30ms, with absolute scroll - // position from 10 to 30. The AverageLag should be: - // (0.5*(10px + 30px)*20ms/20ms) = 20px. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(20, 1))); - - // Another ScrollBegin to flush unfinished frames. - // event_time doesn't matter here because the previous frames' lag are - // compute from their frame_time. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, scroll_delta); - // The to unfinished frames' lag are (finger_positon-rendered_position)*time, - // AverageLag is ((30px-10px)*10ms+(30px-20px)*10ms)/20ms = 15px. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(14, 1))); -} - -// Test that multiple latency being flush in the same frame swap. -TEST_F(AverageLagTrackerTest, TwoLatencyInfoInSameFrame) { - // ScrollBegin - base::TimeTicks event_time = MillisecondsToTimeTicks(10); - base::TimeTicks frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, - -10 /* scroll_delta */); - - // ScrollUpdate with event_time >= ScrollBegin frame_time will generate - // a histogram for AverageLag.ScrollBegin. - event_time = MillisecondsToTimeTicks(20); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - -10 /* scroll_delta */); - - // Absolute position from -10 to -20. The AverageLag should be: - // (0.5*(10px + 20px)*10ms/10ms) = 15px. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(14, 1))); - - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - 5 /* scroll_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - // The ScrollUpdates are at t=20ms, finger_pos=-20px, rendered_pos=-10px, - // at t=25ms, finger_pos=-15px, rendered_pos=-10px; - // To t=30ms both events get flush. - // AverageLag is (0.5*(10px+5px)*5ms + 5px*5ms)/10ms = 6.25px - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(6, 1))); -} - -// Test the case that switching direction causes lag at current frame -// time and previous frame time are in different direction. -TEST_F(AverageLagTrackerTest, ChangeDirectionInFrame) { - // ScrollBegin - base::TimeTicks event_time = MillisecondsToTimeTicks(10); - base::TimeTicks frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, - 10 /* scroll_delta */); - - // At t=20, lag = 10px. - event_time = MillisecondsToTimeTicks(20); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - 10 /* scroll_delta */); - - // At t=30, lag = -10px. - event_time = MillisecondsToTimeTicks(30); - frame_time = MillisecondsToTimeTicks(40); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - -20 /* scroll_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - // From t=20 to t=30, lag_area=2*(0.5*10px*5ms)=50px*ms. - // From t=30 to t=40, lag_area=20px*10ms=200px*ms - // AverageLag = (50+200)/20 = 12.5px. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(12, 1))); -} - -// A simple case without scroll prediction to compare with the two with -// prediction cases below. -TEST_F(AverageLagTrackerTest, NoScrollPrediction) { - // ScrollBegin, at t=5, finger_pos=5px. - base::TimeTicks event_time = MillisecondsToTimeTicks(5); - base::TimeTicks frame_time = MillisecondsToTimeTicks(10); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, - 5 /* scroll_delta */); - - // ScrollUpdate, at t=15, finger_pos=15px. - event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - 10 /* scroll_delta */); - - // ScrollUpdate, at t=25, finger_pos=25px. - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, - 10 /* scroll_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - // Prediction hasn't take affect on ScrollBegin so it'll stay the same. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(7, 1))); - // At t=10, finger_pos = 10px, rendered_pos = 5px. - // At t=20, finger_pos = 20px, rendered_pos = 15px. - // At t=30, finger_pos = 25px, rendered_pos = 25px. - // AverageLag = ((5px+15px)*10ms/2 + (5px+10px)*5ms/2 + 10px*5ms)/20ms - // = 9.375 - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(9, 1))); -} - -// Test AverageLag with perfect scroll prediction. -TEST_F(AverageLagTrackerTest, ScrollPrediction) { - // ScrollBegin, at t=5, finger_pos=5px. - // Predict frame_time=10, predicted_pos = 10px. - base::TimeTicks event_time = MillisecondsToTimeTicks(5); - base::TimeTicks frame_time = MillisecondsToTimeTicks(10); - SyntheticTouchScrollBeginLatencyInfo( - event_time, frame_time, 5 /* scroll_delta */, 10 /* predicted_delta */); - - // ScrollUpdate, at t=15, finger_pos=15px. - // Predict frame_time=20, predicted_pos = 20px. - event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 10 /* predicted_delta */); - - // ScrollUpdate, at t=25, finger_pos=25px. - // Predict frame_time=30, predicted_pos = 30px. - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 10 /* predicted_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - // Prediction hasn't take affect on ScrollBegin so it'll stay the same. - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(7, 1))); - // At t=10, finger_pos = 10px, rendered_pos = 10px. - // At t=20, finger_pos = 20px, rendered_pos = 20px. - // At t=30, finger_pos = 25px, rendered_pos = 30px. - // AverageLag = ((0px+10px)*10ms/2 + (0px+5px)*10ms/2 + 5px*5ms)/20ms - // = 4.375px - // AverageLag (w/o prediction) - // ((5px+15px)*10ms/2 + (5px+10px)*5ms/2 + 10px*5ms)/20ms - // = 9.375px - // Positive effect of prediction = 5px - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(4, 1))); - EXPECT_THAT( - histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive"), - ElementsAre(Bucket(5, 1))); - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative", 0); -} - -// Test AverageLag with imperfect scroll prediction. -TEST_F(AverageLagTrackerTest, ImperfectScrollPrediction) { - // ScrollBegin, at t=5, finger_pos=5px. - // Predict frame_time=10, predicted_pos(over) = 12px. - base::TimeTicks event_time = MillisecondsToTimeTicks(5); - base::TimeTicks frame_time = MillisecondsToTimeTicks(10); - SyntheticTouchScrollBeginLatencyInfo( - event_time, frame_time, 5 /* scroll_delta */, 12 /* predicted_delta */); - - // ScrollUpdate, at t=15, finger_pos=15px. - // Predict frame_time=20, predicted_pos(under) = 17px. - event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 5 /* predicted_delta */); - - // ScrollUpdate, at t=25, finger_pos=25px. - // Predict frame_time=30, predicted_pos(over) = 31px. - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 14 /* predicted_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(7, 1))); - // AverageLag = ((2px*2ms/2+8px*8ms/2)+ ((3px+8px)*5ms/2+8px*5ms))/20ms - // = 5.075px - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(5, 1))); - // AverageLag (w/o prediction = - // ((5px+15px)*10ms/2 + (5px+10px)*5ms/2 + 10px*5ms)/20ms - // = 9.375px - // Positive effect of prediction = 4.3px - EXPECT_THAT( - histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive"), - ElementsAre(Bucket(4, 1))); - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative", 0); -} - -TEST_F(AverageLagTrackerTest, NegativePredictionEffect) { - // ScrollBegin, at t=5, finger_pos=5px. - // Predict frame_time=10, predicted_pos(over) = 20px. - base::TimeTicks event_time = MillisecondsToTimeTicks(5); - base::TimeTicks frame_time = MillisecondsToTimeTicks(10); - SyntheticTouchScrollBeginLatencyInfo( - event_time, frame_time, 5 /* scroll_delta */, 20 /* predicted_delta */); - - // ScrollUpdate, at t=15, finger_pos=15px. - // Predict frame_time=20, predicted_pos(over) = 60px. - event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 40 /* predicted_delta */); - - // ScrollUpdate, at t=25, finger_pos=25px. - // Predict frame_time=30, predicted_pos(over) = 60px. - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 0 /* predicted_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(7, 1))); - // AverageLag = ((10px+0px)*10ms/2)+ ((40px+35px)*5ms/2+35px*5ms))/20ms - // = 20.625px - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(20, 1))); - // AverageLag (w/o prediction = - // ((5px+15px)*10ms/2 + (5px+10px)*5ms/2 + 10px*5ms)/20ms - // = 9.375px - // Negative effect of prediction = 11.25 - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive", 0); - EXPECT_THAT( - histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative"), - ElementsAre(Bucket(11, 1))); -} - -TEST_F(AverageLagTrackerTest, NoPredictionEffect) { - // ScrollBegin, at t=5, finger_pos=5px. - // Predict frame_time=10, predicted_pos(over) = 25px. - base::TimeTicks event_time = MillisecondsToTimeTicks(5); - base::TimeTicks frame_time = MillisecondsToTimeTicks(10); - SyntheticTouchScrollBeginLatencyInfo( - event_time, frame_time, 5 /* scroll_delta */, 25 /* predicted_delta */); - - // ScrollUpdate, at t=15, finger_pos=15px. - // Predict frame_time=20, predicted_pos(over) = 32px. - event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 7 /* predicted_delta */); - - // ScrollUpdate, at t=25, finger_pos=25px. - // Predict frame_time=30, predicted_pos(over) = 37px. - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo( - event_time, frame_time, 10 /* scroll_delta */, 5 /* predicted_delta */); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollBegin.Touch.AverageLag"), - ElementsAre(Bucket(7, 1))); - // AverageLag = ((15px+5px)*10ms/2 + (12px+7px)*5ms/2 + 7px*5ms)/20ms - // = 9.125px - EXPECT_THAT(histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag"), - ElementsAre(Bucket(9, 1))); - // AverageLag (w/o prediction) = - // ((5px+15px)*10ms/2 + (5px+10px)*5ms/2 + 10px*5ms)/20ms - // = 9.375px - // Prediction slightly positive, we should see a 0 bucket in - // PredictionPositive UMA - EXPECT_THAT( - histogram_tester().GetAllSamples( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionPositive"), - ElementsAre(Bucket(0, 1))); - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag.PredictionNegative", 0); -} - -// Tests that when an event arrives out-of-order, the average lag tracker -// properly ignores it. -TEST_F(AverageLagTrackerTest, EventOutOfOrder) { - base::TimeTicks event_time = MillisecondsToTimeTicks(5); - base::TimeTicks frame_time = MillisecondsToTimeTicks(10); - float scroll_delta = 5.f; - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, scroll_delta); - - event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(20); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, scroll_delta); - - event_time = MillisecondsToTimeTicks(25); - frame_time = MillisecondsToTimeTicks(30); - SyntheticTouchScrollUpdateLatencyInfo(event_time, frame_time, scroll_delta); - - // A ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(1000); - frame_time = MillisecondsToTimeTicks(1000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag", 1); - - // Send an event whose timestamp is earlier than the most recent event, - // representing an event that gets process out of order. - base::TimeTicks earlier_event_time = MillisecondsToTimeTicks(15); - frame_time = MillisecondsToTimeTicks(1010); - SyntheticTouchScrollUpdateLatencyInfo(earlier_event_time, frame_time, - scroll_delta); - - // Another ScrollBegin to flush unfinished frames. - event_time = MillisecondsToTimeTicks(2000); - frame_time = MillisecondsToTimeTicks(2000); - SyntheticTouchScrollBeginLatencyInfo(event_time, frame_time, 0); - - // Ensure that the event was ignored. - histogram_tester().ExpectTotalCount( - "Event.Latency.ScrollUpdate.Touch.AverageLag", 1); -} - -} // namespace -} // namespace ui |