Revert of Move ScrollAnimatorTest.cpp to Source/platform/scroll/.

third_party/WebKit/Source/web/tests/ScrollAnimatorTest.cpp

+/*
+ * Copyright (C) 2010 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1.  Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ * 2.  Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+// Tests for the ScrollAnimator class.
+
+#include "config.h"
+#include "platform/scroll/ScrollAnimator.h"
+
+#include "platform/Logging.h"
+#include "platform/geometry/FloatPoint.h"
+#include "platform/geometry/IntRect.h"
+#include "platform/scroll/ScrollAnimatorBase.h"
+#include "platform/scroll/ScrollableArea.h"
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+namespace blink {
+
+using testing::AtLeast;
+using testing::Return;
+using testing::_;
+
+class MockScrollableArea : public NoBaseWillBeGarbageCollectedFinalized<MockScrollableArea>, public ScrollableArea {
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MockScrollableArea);
+public:
+    static PassOwnPtrWillBeRawPtr<MockScrollableArea> create(bool scrollAnimatorEnabled)
+    {
+        return adoptPtrWillBeNoop(new MockScrollableArea(scrollAnimatorEnabled));
+    }
+
+    MOCK_CONST_METHOD0(isActive, bool());
+    MOCK_CONST_METHOD1(scrollSize, int(ScrollbarOrientation));
+    MOCK_METHOD2(invalidateScrollbar, void(Scrollbar*, const IntRect&));
+    MOCK_CONST_METHOD0(isScrollCornerVisible, bool());
+    MOCK_CONST_METHOD0(scrollCornerRect, IntRect());
+    MOCK_METHOD2(setScrollOffset, void(const IntPoint&, ScrollType));
+    MOCK_METHOD2(invalidateScrollbarRect, void(Scrollbar*, const IntRect&));
+    MOCK_METHOD1(invalidateScrollCornerRect, void(const IntRect&));
+    MOCK_CONST_METHOD0(enclosingScrollableArea, ScrollableArea*());
+    MOCK_CONST_METHOD0(minimumScrollPosition, IntPoint());
+    MOCK_CONST_METHOD0(maximumScrollPosition, IntPoint());
+    MOCK_CONST_METHOD1(visibleContentRect, IntRect(IncludeScrollbarsInRect));
+    MOCK_CONST_METHOD0(contentsSize, IntSize());
+    MOCK_CONST_METHOD0(scrollbarsCanBeActive, bool());
+    MOCK_CONST_METHOD0(scrollableAreaBoundingBox, IntRect());
+
+    bool userInputScrollable(ScrollbarOrientation) const override { return true; }
+    bool shouldPlaceVerticalScrollbarOnLeft() const override { return false; }
+    IntPoint scrollPosition() const override { return IntPoint(); }
+    int visibleHeight() const override { return 768; }
+    int visibleWidth() const override { return 1024; }
+    bool scrollAnimatorEnabled() const override { return m_scrollAnimatorEnabled; }
+    int pageStep(ScrollbarOrientation) const override { return 0; }
+
+    DEFINE_INLINE_VIRTUAL_TRACE()
+    {
+        ScrollableArea::trace(visitor);
+    }
+
+private:
+    explicit MockScrollableArea(bool scrollAnimatorEnabled)
+        : m_scrollAnimatorEnabled(scrollAnimatorEnabled) { }
+
+    bool m_scrollAnimatorEnabled;
+};
+
+class MockScrollAnimatorNone : public ScrollAnimator {
+public:
+    static PassOwnPtr<MockScrollAnimatorNone> create(ScrollableArea* scrollableArea)
+    {
+        return adoptPtr(new MockScrollAnimatorNone(scrollableArea));
+    }
+
+    float currentX() { return m_currentPosX; }
+    float currentY() { return m_currentPosY; }
+
+    FloatPoint m_fp;
+    int m_count;
+
+    void reset()
+    {
+        stopAnimationTimerIfNeeded();
+        m_currentPosX = 0;
+        m_currentPosY = 0;
+        m_horizontalData.reset();
+        m_verticalData.reset();
+        m_fp = FloatPoint::zero();
+        m_count = 0;
+    }
+
+    virtual void fireUpAnAnimation(FloatPoint fp)
+    {
+        m_fp = fp;
+        m_count++;
+    }
+
+private:
+    explicit MockScrollAnimatorNone(ScrollableArea* scrollableArea)
+        : ScrollAnimator(scrollableArea) { }
+
+};
+
+TEST(ScrollAnimatorEnabled, Enabled)
+{
+    OwnPtrWillBeRawPtr<MockScrollableArea> scrollableArea = MockScrollableArea::create(true);
+    OwnPtr<MockScrollAnimatorNone> scrollAnimatorNone = MockScrollAnimatorNone::create(scrollableArea.get());
+
+    EXPECT_CALL(*scrollableArea, minimumScrollPosition()).Times(AtLeast(1)).WillRepeatedly(Return(IntPoint()));
+    EXPECT_CALL(*scrollableArea, maximumScrollPosition()).Times(AtLeast(1)).WillRepeatedly(Return(IntPoint(1000, 1000)));
+    EXPECT_CALL(*scrollableArea, setScrollOffset(_, _)).Times(4);
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByLine, 100, 1);
+    EXPECT_NE(100, scrollAnimatorNone->currentX());
+    EXPECT_NE(0, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByPage, 100, 1);
+    EXPECT_NE(100, scrollAnimatorNone->currentX());
+    EXPECT_NE(0, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByPixel, 4, 25);
+    EXPECT_NE(100, scrollAnimatorNone->currentX());
+    EXPECT_NE(0, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByPrecisePixel, 4, 25);
+    EXPECT_EQ(100, scrollAnimatorNone->currentX());
+    EXPECT_NE(0, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+}
+
+TEST(ScrollAnimatorEnabled, Disabled)
+{
+    OwnPtrWillBeRawPtr<MockScrollableArea> scrollableArea = MockScrollableArea::create(false);
+    OwnPtr<MockScrollAnimatorNone> scrollAnimatorNone = MockScrollAnimatorNone::create(scrollableArea.get());
+
+    EXPECT_CALL(*scrollableArea, minimumScrollPosition()).Times(AtLeast(1)).WillRepeatedly(Return(IntPoint()));
+    EXPECT_CALL(*scrollableArea, maximumScrollPosition()).Times(AtLeast(1)).WillRepeatedly(Return(IntPoint(1000, 1000)));
+    EXPECT_CALL(*scrollableArea, setScrollOffset(_, _)).Times(4);
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByLine, 100, 1);
+    EXPECT_EQ(100, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByPage, 100, 1);
+    EXPECT_EQ(100, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByDocument, 100, 1);
+    EXPECT_EQ(100, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+
+    scrollAnimatorNone->userScroll(HorizontalScrollbar, ScrollByPixel, 100, 1);
+    EXPECT_EQ(100, scrollAnimatorNone->currentX());
+    EXPECT_EQ(0, scrollAnimatorNone->currentY());
+    scrollAnimatorNone->reset();
+}
+
+class ScrollAnimatorTest : public testing::Test {
+public:
+    struct SavePerAxisData : public ScrollAnimator::PerAxisData {
+        SavePerAxisData(const ScrollAnimator::PerAxisData& data)
+            : ScrollAnimator::PerAxisData(0, 768)
+            , m_mockScrollableArea(MockScrollableArea::create(true))
+            , m_mockScrollAnimatorNone(MockScrollAnimatorNone::create(m_mockScrollableArea.get()))
+        {
+            this->m_currentVelocity = data.m_currentVelocity;
+            this->m_desiredPosition = data.m_desiredPosition;
+            this->m_desiredVelocity = data.m_desiredVelocity;
+            this->m_startPosition = data.m_startPosition;
+            this->m_startTime = data.m_startTime;
+            this->m_startVelocity = data.m_startVelocity;
+            this->m_animationTime = data.m_animationTime;
+            this->m_lastAnimationTime = data.m_lastAnimationTime;
+            this->m_attackPosition = data.m_attackPosition;
+            this->m_attackTime = data.m_attackTime;
+            this->m_attackCurve = data.m_attackCurve;
+            this->m_releasePosition = data.m_releasePosition;
+            this->m_releaseTime = data.m_releaseTime;
+            this->m_releaseCurve = data.m_releaseCurve;
+        }
+
+        bool operator==(const SavePerAxisData& other) const
+        {
+            return m_currentVelocity == other.m_currentVelocity && m_desiredPosition == other.m_desiredPosition && m_desiredVelocity == other.m_desiredVelocity && m_startPosition == other.m_startPosition && m_startTime == other.m_startTime && m_startVelocity == other.m_startVelocity && m_animationTime == other.m_animationTime && m_lastAnimationTime == other.m_lastAnimationTime && m_attackPosition == other.m_attackPosition && m_attackTime == other.m_attackTime && m_attackCurve == other.m_attackCurve && m_releasePosition == other.m_releasePosition && m_releaseTime == other.m_releaseTime && m_releaseCurve == other.m_releaseCurve;
+        }
+        OwnPtrWillBePersistent<MockScrollableArea> m_mockScrollableArea;
+        OwnPtr<MockScrollAnimatorNone> m_mockScrollAnimatorNone;
+    };
+
+    ScrollAnimatorTest()
+        : m_mockScrollableArea(MockScrollableArea::create(true))
+        , m_mockScrollAnimatorNone(MockScrollAnimatorNone::create(m_mockScrollableArea.get()))
+    {
+    }
+
+    void SetUp() override
+    {
+        m_currentPosition = 100;
+        m_data = new ScrollAnimator::PerAxisData(&m_currentPosition, 768);
+    }
+    void TearDown() override
+    {
+        delete m_data;
+    }
+
+    void reset();
+    bool updateDataFromParameters(float step, float multiplier, float minScrollPos, float maxScrollPos, double currentTime, ScrollAnimator::Parameters*);
+    bool updateDataFromParameters(float step, float multiplier, float scrollableSize, double currentTime, ScrollAnimator::Parameters*);
+    bool animateScroll(double currentTime);
+
+    double attackArea(ScrollAnimator::Curve, double startT, double endT);
+    double releaseArea(ScrollAnimator::Curve, double startT, double endT);
+    double attackCurve(ScrollAnimator::Curve, double deltaT, double curveT, double startPosition, double attackPosition);
+    double releaseCurve(ScrollAnimator::Curve, double deltaT, double curveT, double releasePosition, double desiredPosition);
+    double coastCurve(ScrollAnimator::Curve, double factor);
+
+    void curveTestInner(ScrollAnimator::Curve, double step, double time);
+    void curveTest(ScrollAnimator::Curve);
+
+    void checkDesiredPosition(float expectedPosition);
+    void checkSoftLanding(float expectedPosition);
+
+    static double kTickTime;
+    static double kAnimationTime;
+    static double kStartTime;
+    static double kEndTime;
+    float m_currentPosition;
+    OwnPtrWillBePersistent<MockScrollableArea> m_mockScrollableArea;
+    OwnPtr<MockScrollAnimatorNone> m_mockScrollAnimatorNone;
+    bool m_scrollingDown;
+    ScrollAnimator::PerAxisData* m_data;
+};
+
+double ScrollAnimatorTest::kTickTime = 1 / 60.0;
+double ScrollAnimatorTest::kAnimationTime = 0.01;
+double ScrollAnimatorTest::kStartTime = 10.0;
+double ScrollAnimatorTest::kEndTime = 20.0;
+
+void ScrollAnimatorTest::reset()
+{
+    m_data->reset();
+    m_scrollingDown = true;
+}
+
+bool ScrollAnimatorTest::updateDataFromParameters(float step, float multiplier, float minScrollPos, float maxScrollPos, double currentTime, ScrollAnimator::Parameters* parameters)
+{
+    if (step * multiplier)
+        m_scrollingDown = (step * multiplier > 0);
+
+    double oldVelocity = m_data->m_currentVelocity;
+    double oldDesiredVelocity = m_data->m_desiredVelocity;
+    double oldTimeLeft = m_data->m_animationTime - (m_data->m_lastAnimationTime - m_data->m_startTime);
+    bool result = m_data->updateDataFromParameters(step, multiplier, minScrollPos, maxScrollPos, currentTime, parameters);
+    if (m_scrollingDown)
+        EXPECT_LE(oldVelocity, m_data->m_currentVelocity);
+    else
+        EXPECT_GE(oldVelocity, m_data->m_currentVelocity);
+
+    double deltaTime = m_data->m_lastAnimationTime - m_data->m_startTime;
+    double timeLeft = m_data->m_animationTime - deltaTime;
+    double releaseTimeLeft = std::min(timeLeft, m_data->m_releaseTime);
+    double attackTimeLeft = std::max(0., m_data->m_attackTime - deltaTime);
+    double sustainTimeLeft = std::max(0., timeLeft - releaseTimeLeft - attackTimeLeft);
+
+    // If we're getting near the finish, the desired velocity can decrease since the time left gets increased.
+    if (step * multiplier) {
+        double allowedVelocityDecreaseFactor = 0.99 * oldTimeLeft / timeLeft;
+        allowedVelocityDecreaseFactor *= allowedVelocityDecreaseFactor;
+        if (m_scrollingDown)
+            EXPECT_LE(oldDesiredVelocity * allowedVelocityDecreaseFactor, m_data->m_desiredVelocity);
+        else
+            EXPECT_GE(oldDesiredVelocity * allowedVelocityDecreaseFactor, m_data->m_desiredVelocity);
+
+        double startPosition = attackTimeLeft ? m_data->m_attackPosition : m_currentPosition;
+        double expectedReleasePosition = startPosition + sustainTimeLeft * m_data->m_desiredVelocity;
+        EXPECT_NEAR(expectedReleasePosition, m_data->m_releasePosition, result ? .0001 : 1);
+    }
+
+    return result;
+}
+
+bool ScrollAnimatorTest::updateDataFromParameters(float step, float multiplier, float scrollableSize, double currentTime, ScrollAnimator::Parameters* parameters)
+{
+    return updateDataFromParameters(step, multiplier, 0, scrollableSize, currentTime, parameters);
+}
+
+bool ScrollAnimatorTest::animateScroll(double currentTime)
+{
+    double oldPosition = *m_data->m_currentPosition;
+    bool testEstimatedMaxVelocity = m_data->m_startTime + m_data->m_animationTime - m_data->m_lastAnimationTime > m_data->m_releaseTime;
+
+    bool result = m_data->animateScroll(currentTime);
+
+    double deltaTime = m_data->m_lastAnimationTime - m_data->m_startTime;
+    double timeLeft = m_data->m_animationTime - deltaTime;
+    double releaseTimeLeft = std::min(timeLeft, m_data->m_releaseTime);
+    double attackTimeLeft = std::max(0., m_data->m_attackTime - deltaTime);
+    double sustainTimeLeft = std::max(0., timeLeft - releaseTimeLeft - attackTimeLeft);
+    double distanceLeft = m_data->m_desiredPosition - *m_data->m_currentPosition;
+
+    if (m_scrollingDown) {
+        EXPECT_LE(0, m_data->m_currentVelocity);
+        EXPECT_LE(oldPosition, *m_data->m_currentPosition);
+    } else {
+        EXPECT_GE(0, m_data->m_currentVelocity);
+        EXPECT_GE(oldPosition, *m_data->m_currentPosition);
+    }
+    EXPECT_GE(fabs(m_data->m_desiredVelocity) * 2, fabs(m_data->m_currentVelocity));
+    if (testEstimatedMaxVelocity)
+        EXPECT_GE(fabs(distanceLeft / sustainTimeLeft) * 1.2, fabs(m_data->m_currentVelocity));
+
+    return result;
+}
+
+double ScrollAnimatorTest::attackArea(ScrollAnimator::Curve curve, double startT, double endT)
+{
+    return ScrollAnimator::PerAxisData::attackArea(curve, startT, endT);
+}
+
+double ScrollAnimatorTest::releaseArea(ScrollAnimator::Curve curve, double startT, double endT)
+{
+    return ScrollAnimator::PerAxisData::releaseArea(curve, startT, endT);
+}
+
+double ScrollAnimatorTest::attackCurve(ScrollAnimator::Curve curve, double deltaT, double curveT, double startPosition, double attackPosition)
+{
+    return ScrollAnimator::PerAxisData::attackCurve(curve, deltaT, curveT, startPosition, attackPosition);
+}
+
+double ScrollAnimatorTest::releaseCurve(ScrollAnimator::Curve curve, double deltaT, double curveT, double releasePosition, double desiredPosition)
+{
+    return ScrollAnimator::PerAxisData::releaseCurve(curve, deltaT, curveT, releasePosition, desiredPosition);
+}
+
+double ScrollAnimatorTest::coastCurve(ScrollAnimator::Curve curve, double factor)
+{
+    return ScrollAnimator::PerAxisData::coastCurve(curve, factor);
+}
+
+void ScrollAnimatorTest::curveTestInner(ScrollAnimator::Curve curve, double step, double time)
+{
+    const double kPosition = 1000;
+
+    double oldPos = 0;
+    double oldVelocity = 0;
+    double accumulate = 0;
+
+    for (double t = step ; t <= time ; t += step) {
+        double newPos = attackCurve(curve, t, time, 0, kPosition);
+        double delta = newPos - oldPos;
+        double velocity = delta / step;
+        double velocityDelta = velocity - oldVelocity;
+
+        accumulate += (oldPos + newPos) / 2 * (step / time);
+        oldPos = newPos;
+        oldVelocity = velocity;
+        if (curve != ScrollAnimator::Bounce) {
+            EXPECT_LE(-.0001, velocityDelta);
+            EXPECT_LT(0, delta);
+        }
+
+        double area = attackArea(curve, 0, t / time) * kPosition;
+        EXPECT_LE(0, area);
+        EXPECT_NEAR(accumulate, area, 1.0);
+    }
+
+    oldPos = 0;
+    oldVelocity *= 2;
+    accumulate = releaseArea(curve, 0, 1) * kPosition;
+    for (double t = step ; t <= time ; t += step) {
+        double newPos = releaseCurve(curve, t, time, 0, kPosition);
+        double delta = newPos - oldPos;
+        double velocity = delta / step;
+        double velocityDelta = velocity - oldVelocity;
+
+        accumulate -= (kPosition - (oldPos + newPos) / 2) * (step / time);
+        oldPos = newPos;
+        oldVelocity = velocity;
+        if (curve != ScrollAnimator::Bounce) {
+            EXPECT_GE(0.01, velocityDelta);
+            EXPECT_LT(0, delta);
+        }
+
+        double area = releaseArea(curve, t / time, 1) * kPosition;
+        EXPECT_LE(0, area);
+        EXPECT_NEAR(accumulate, area, 1.0);
+    }
+}
+
+void ScrollAnimatorTest::curveTest(ScrollAnimator::Curve curve)
+{
+    curveTestInner(curve, 0.01, 0.25);
+    curveTestInner(curve, 0.2, 10);
+    curveTestInner(curve, 0.025, 10);
+    curveTestInner(curve, 0.01, 1);
+    curveTestInner(curve, 0.25, 40);
+}
+
+void ScrollAnimatorTest::checkDesiredPosition(float expectedPosition)
+{
+    EXPECT_EQ(expectedPosition, m_data->m_desiredPosition);
+}
+
+void ScrollAnimatorTest::checkSoftLanding(float expectedPosition)
+{
+    EXPECT_EQ(expectedPosition, m_currentPosition);
+    EXPECT_LE(m_data->m_desiredVelocity / 2, m_data->m_currentVelocity);
+}
+
+TEST_F(ScrollAnimatorTest, CurveMathLinear)
+{
+    curveTest(ScrollAnimator::Linear);
+}
+
+TEST_F(ScrollAnimatorTest, CurveMathQuadratic)
+{
+    curveTest(ScrollAnimator::Quadratic);
+}
+
+TEST_F(ScrollAnimatorTest, CurveMathCubic)
+{
+    curveTest(ScrollAnimator::Cubic);
+}
+
+TEST_F(ScrollAnimatorTest, CurveMathQuartic)
+{
+    curveTest(ScrollAnimator::Quartic);
+}
+
+TEST_F(ScrollAnimatorTest, CurveMathBounce)
+{
+    curveTest(ScrollAnimator::Bounce);
+}
+
+TEST_F(ScrollAnimatorTest, CurveMathCoast)
+{
+    for (double t = .25; t < 1; t += .25) {
+        EXPECT_EQ(t, coastCurve(ScrollAnimator::Linear, t));
+        EXPECT_LT(t, coastCurve(ScrollAnimator::Quadratic, t));
+        EXPECT_LT(t, coastCurve(ScrollAnimator::Cubic, t));
+        EXPECT_LT(coastCurve(ScrollAnimator::Quadratic, t), coastCurve(ScrollAnimator::Cubic, t));
+        EXPECT_LT(t, coastCurve(ScrollAnimator::Quartic, t));
+        EXPECT_LT(coastCurve(ScrollAnimator::Cubic, t), coastCurve(ScrollAnimator::Quartic, t));
+    }
+}
+
+TEST_F(ScrollAnimatorTest, ScrollOnceLinear)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Linear, 3 * kTickTime, ScrollAnimator::Linear, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollOnceQuadratic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollLongQuadratic)
+{
+    ScrollAnimator::Parameters parameters(true, 20 * kTickTime, 0, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollQuadraticNoSustain)
+{
+    ScrollAnimator::Parameters parameters(true, 8 * kTickTime, 0, ScrollAnimator::Quadratic, 4 * kTickTime, ScrollAnimator::Quadratic, 4 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollQuadraticSmoothed)
+{
+    ScrollAnimator::Parameters parameters(true, 8 * kTickTime, 8 * kTickTime, ScrollAnimator::Quadratic, 4 * kTickTime, ScrollAnimator::Quadratic, 4 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollOnceCubic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollOnceQuartic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Quartic, 3 * kTickTime, ScrollAnimator::Quartic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollOnceShort)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    for (double t = kStartTime; result && t < kEndTime; t += kTickTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollTwiceQuadratic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    result = result && animateScroll(t);
+    double before = m_currentPosition;
+    result = result && updateDataFromParameters(1, 40, 1000, t, &parameters);
+    result = result && animateScroll(t);
+    double after = m_currentPosition;
+    EXPECT_NEAR(before, after, 10);
+
+    t += kAnimationTime;
+
+    result = result && animateScroll(t);
+    before = m_currentPosition;
+    result = result && updateDataFromParameters(1, 40, 1000, t, &parameters);
+    result = result && animateScroll(t);
+    after = m_currentPosition;
+    EXPECT_NEAR(before, after, 10);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollLotsQuadratic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 10000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    for (int i = 0; i < 20; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        result = result && updateDataFromParameters(3, 40, 10000, t, &parameters);
+    }
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollLotsQuadraticSmoothed)
+{
+    ScrollAnimator::Parameters parameters(true, 10 * kTickTime, 6 * kTickTime, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Quadratic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 10000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    for (int i = 0; i < 20; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        result = result && updateDataFromParameters(3, 40, 10000, t, &parameters);
+    }
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollTwiceCubic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    result = result && animateScroll(t);
+    double before = m_currentPosition;
+    result = result && updateDataFromParameters(1, 40, 1000, t, &parameters);
+    result = result && animateScroll(t);
+    double after = m_currentPosition;
+    EXPECT_NEAR(before, after, 10);
+
+    t += kAnimationTime;
+
+    result = result && animateScroll(t);
+    before = m_currentPosition;
+    result = result && updateDataFromParameters(1, 40, 1000, t, &parameters);
+    result = result && animateScroll(t);
+    after = m_currentPosition;
+    EXPECT_NEAR(before, after, 10);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollLotsCubic)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 10000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    for (int i = 0; i < 20; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        result = result && updateDataFromParameters(3, 40, 10000, t, &parameters);
+    }
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollLotsCubicSmoothed)
+{
+    ScrollAnimator::Parameters parameters(true, 10 * kTickTime, 6 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 10000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    for (int i = 0; i < 20; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        result = result && updateDataFromParameters(3, 40, 10000, t, &parameters);
+    }
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollWheelTrace)
+{
+    ScrollAnimator::Parameters parameters(true, 11 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    // Constructed from an actual scroll wheel trace that exhibited a glitch.
+    bool result = updateDataFromParameters(1, 53.33f, 1000, 100.5781f, &parameters);
+    result = animateScroll(100.5933);
+    result = result && animateScroll(100.6085);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.6485f, &parameters);
+    result = result && animateScroll(100.6515);
+    result = result && animateScroll(100.6853);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.6863f, &parameters);
+    result = result && animateScroll(100.7005);
+    result = result && animateScroll(100.7157);
+    result = result && animateScroll(100.7312);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.7379f, &parameters);
+    result = result && animateScroll(100.7464);
+    result = result && animateScroll(100.7617);
+    result = result && animateScroll(100.7775);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.7779f, &parameters);
+    for (double t = 100.7928; result && t < 200; t += 0.015)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollWheelTraceSmoothed)
+{
+    ScrollAnimator::Parameters parameters(true, 11 * kTickTime, 7 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    // Constructed from an actual scroll wheel trace that exhibited a glitch.
+    bool result = updateDataFromParameters(1, 53.33f, 1000, 100.5781f, &parameters);
+    result = animateScroll(100.5933);
+    result = result && animateScroll(100.6085);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.6485f, &parameters);
+    result = result && animateScroll(100.6515);
+    result = result && animateScroll(100.6853);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.6863f, &parameters);
+    result = result && animateScroll(100.7005);
+    result = result && animateScroll(100.7157);
+    result = result && animateScroll(100.7312);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.7379f, &parameters);
+    result = result && animateScroll(100.7464);
+    result = result && animateScroll(100.7617);
+    result = result && animateScroll(100.7775);
+    result = result && updateDataFromParameters(1, 53.33f, 1000, 100.7779f, &parameters);
+    for (double t = 100.7928; result && t < 200; t += 0.015)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, LinuxTrackPadTrace)
+{
+    ScrollAnimator::Parameters parameters(true, 11 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    bool result = updateDataFromParameters(1.00, 60.00, 1000, 100.6863, &parameters);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.6897, &parameters);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7001, &parameters);
+    result = result && animateScroll(100.7015);
+    result = result && animateScroll(100.7169);
+    result = result && updateDataFromParameters(1.00, 40.00, 1000, 100.7179, &parameters);
+    result = result && animateScroll(100.7322);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7332, &parameters);
+    result = result && animateScroll(100.7491);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7519, &parameters);
+    result = result && animateScroll(100.7676);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7698, &parameters);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7830, &parameters);
+    result = result && animateScroll(100.7834);
+    result = result && animateScroll(100.7997);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8019, &parameters);
+    result = result && animateScroll(100.8154);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8241, &parameters);
+    result = result && animateScroll(100.8335);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8465, &parameters);
+    result = result && animateScroll(100.8513);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8623, &parameters);
+    for (double t = 100.8674; result && t < 200; t += 0.015)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, LinuxTrackPadTraceSmoothed)
+{
+    ScrollAnimator::Parameters parameters(true, 11 * kTickTime, 7 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    bool result = updateDataFromParameters(1.00, 60.00, 1000, 100.6863, &parameters);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.6897, &parameters);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7001, &parameters);
+    result = result && animateScroll(100.7015);
+    result = result && animateScroll(100.7169);
+    result = result && updateDataFromParameters(1.00, 40.00, 1000, 100.7179, &parameters);
+    result = result && animateScroll(100.7322);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7332, &parameters);
+    result = result && animateScroll(100.7491);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7519, &parameters);
+    result = result && animateScroll(100.7676);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7698, &parameters);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.7830, &parameters);
+    result = result && animateScroll(100.7834);
+    result = result && animateScroll(100.7997);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8019, &parameters);
+    result = result && animateScroll(100.8154);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8241, &parameters);
+    result = result && animateScroll(100.8335);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8465, &parameters);
+    result = result && animateScroll(100.8513);
+    result = result && updateDataFromParameters(1.00, 20.00, 1000, 100.8623, &parameters);
+    for (double t = 100.8674; result && t < 200; t += 0.015)
+        result = result && animateScroll(t);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollRightToBumperRTL)
+{
+    // Tests that scrolling works for a negative scroll bound. This is the case
+    // for RTL pages where the scroll position is always negative.
+    m_currentPosition = 0;
+    ScrollAnimator::Parameters parameters(true, 10 * kTickTime, 7 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, -20, -200, 0, kStartTime, &parameters));
+    bool result = true;
+    double t = kStartTime;
+    for (int i = 0; i < 10; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        updateDataFromParameters(1, -20, -200, 0, t, &parameters);
+    }
+    checkDesiredPosition(-200);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+    checkSoftLanding(-200);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollDownToBumper)
+{
+    ScrollAnimator::Parameters parameters(true, 10 * kTickTime, 7 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 20, 200, kStartTime, &parameters));
+    bool result = true;
+    double t = kStartTime;
+    for (int i = 0; i < 10; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        updateDataFromParameters(1, 20, 200, t, &parameters);
+    }
+    checkDesiredPosition(200);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+    checkSoftLanding(200);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollUpToBumper)
+{
+    ScrollAnimator::Parameters parameters(true, 10 * kTickTime, 7 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, -20, 200, kStartTime, &parameters));
+    bool result = true;
+    double t = kStartTime;
+    for (int i = 0; i < 10; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        updateDataFromParameters(1, -20, 200, t, &parameters);
+    }
+    checkDesiredPosition(0);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+    checkSoftLanding(0);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollUpToBumperCoast)
+{
+    ScrollAnimator::Parameters parameters(true, 11 * kTickTime, 2 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 1);
+
+    m_currentPosition = 40000;
+    EXPECT_TRUE(updateDataFromParameters(1, -10000, 50000, kStartTime, &parameters));
+    bool result = true;
+    double t = kStartTime;
+    for (int i = 0; i < 10; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        updateDataFromParameters(1, -10000, 50000, t, &parameters);
+    }
+    checkDesiredPosition(0);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+    checkSoftLanding(0);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollDownToBumperCoast)
+{
+    ScrollAnimator::Parameters parameters(true, 11 * kTickTime, 2 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 1);
+
+    m_currentPosition = 10000;
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    bool result = true;
+    double t = kStartTime;
+    for (int i = 0; i < 10; ++i) {
+        t += kAnimationTime;
+        result = result && animateScroll(t);
+        updateDataFromParameters(1, 10000, 50000, t, &parameters);
+    }
+    checkDesiredPosition(50000);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+    checkSoftLanding(50000);
+}
+
+TEST_F(ScrollAnimatorTest, VaryingInputsEquivalency)
+{
+    ScrollAnimator::Parameters parameters(true, 15 * kTickTime, 10 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Linear, 0);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 300, 50000, kStartTime, &parameters));
+    SavePerAxisData dataSingle(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 150, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 150, 50000, kStartTime, &parameters));
+    SavePerAxisData dataDouble(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 100, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 100, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 100, 50000, kStartTime, &parameters));
+    SavePerAxisData dataTriple(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 50, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 50, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 50, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 50, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 50, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 50, 50000, kStartTime, &parameters));
+    SavePerAxisData dataMany(*m_data);
+
+    EXPECT_EQ(dataSingle, dataDouble);
+    EXPECT_EQ(dataSingle, dataTriple);
+    EXPECT_EQ(dataSingle, dataMany);
+}
+
+TEST_F(ScrollAnimatorTest, VaryingInputsEquivalencyCoast)
+{
+    ScrollAnimator::Parameters parameters(true, 15 * kTickTime, 10 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Linear, 1);
+
+    reset();
+    updateDataFromParameters(1, 300, 50000, kStartTime, &parameters);
+    SavePerAxisData dataSingle(*m_data);
+
+    reset();
+    updateDataFromParameters(1, 150, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 150, 50000, kStartTime, &parameters);
+    SavePerAxisData dataDouble(*m_data);
+
+    reset();
+    updateDataFromParameters(1, 100, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 100, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 100, 50000, kStartTime, &parameters);
+    SavePerAxisData dataTriple(*m_data);
+
+    reset();
+    updateDataFromParameters(1, 50, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 50, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 50, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 50, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 50, 50000, kStartTime, &parameters);
+    updateDataFromParameters(1, 50, 50000, kStartTime, &parameters);
+    SavePerAxisData dataMany(*m_data);
+
+    EXPECT_EQ(dataSingle, dataDouble);
+    EXPECT_EQ(dataSingle, dataTriple);
+    EXPECT_EQ(dataSingle, dataMany);
+}
+
+TEST_F(ScrollAnimatorTest, VaryingInputsEquivalencyCoastLarge)
+{
+    ScrollAnimator::Parameters parameters(true, 15 * kTickTime, 10 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Linear, 1);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 30000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataSingle(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 15000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 15000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataDouble(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataTriple(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataMany(*m_data);
+
+    EXPECT_EQ(dataSingle, dataDouble);
+    EXPECT_EQ(dataSingle, dataTriple);
+    EXPECT_EQ(dataSingle, dataMany);
+}
+
+TEST_F(ScrollAnimatorTest, VaryingInputsEquivalencyCoastSteep)
+{
+    ScrollAnimator::Parameters parameters(true, 15 * kTickTime, 10 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Cubic, 5 * kTickTime, ScrollAnimator::Quadratic, 1);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 30000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataSingle(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 15000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 15000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataDouble(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 10000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataTriple(*m_data);
+
+    reset();
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    EXPECT_TRUE(updateDataFromParameters(1, 5000, 50000, kStartTime, &parameters));
+    SavePerAxisData dataMany(*m_data);
+
+    EXPECT_EQ(dataSingle, dataDouble);
+    EXPECT_EQ(dataSingle, dataTriple);
+    EXPECT_EQ(dataSingle, dataMany);
+}
+
+TEST_F(ScrollAnimatorTest, ScrollStopInMiddle)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    result = result && animateScroll(t);
+    EXPECT_TRUE(result);
+    double before = m_currentPosition;
+    result = result && updateDataFromParameters(0, 0, 1000, t, &parameters);
+    EXPECT_FALSE(result);
+    result = result && animateScroll(t);
+    double after = m_currentPosition;
+    EXPECT_EQ(before, after);
+    checkDesiredPosition(after);
+}
+
+TEST_F(ScrollAnimatorTest, ReverseInMiddle)
+{
+    ScrollAnimator::Parameters parameters(true, 7 * kTickTime, 0, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Cubic, 3 * kTickTime, ScrollAnimator::Linear, 0);
+
+    EXPECT_TRUE(updateDataFromParameters(1, 40, 1000, kStartTime, &parameters));
+    bool result = true;
+    double t;
+    for (t = kStartTime; result && t < kStartTime + 1.5 * kTickTime; t += kAnimationTime)
+        result = animateScroll(t);
+
+    result = result && animateScroll(t);
+    EXPECT_TRUE(result);
+    double before = m_currentPosition;
+    result = result && updateDataFromParameters(1, -10, 1000, t, &parameters);
+    EXPECT_TRUE(result);
+    result = result && animateScroll(t);
+    double after = m_currentPosition;
+    EXPECT_GE(before, after);
+
+    t += kAnimationTime;
+    for (; result && t < kEndTime; t += kAnimationTime)
+        result = result && animateScroll(t);
+    EXPECT_GE(before, m_currentPosition);
+}
+
+} // namespace blink