diff --git a/services/inputflinger/tests/Android.bp b/services/inputflinger/tests/Android.bp
index 42b54c7..918e1be 100644
--- a/services/inputflinger/tests/Android.bp
+++ b/services/inputflinger/tests/Android.bp
@@ -46,6 +46,7 @@
         "InputDispatcher_test.cpp",
         "InputReader_test.cpp",
         "InputFlingerService_test.cpp",
+        "LatencyTracker_test.cpp",
         "TestInputListener.cpp",
         "UinputDevice.cpp",
     ],
diff --git a/services/inputflinger/tests/InputDispatcher_test.cpp b/services/inputflinger/tests/InputDispatcher_test.cpp
index 855453e..93aa6ac 100644
--- a/services/inputflinger/tests/InputDispatcher_test.cpp
+++ b/services/inputflinger/tests/InputDispatcher_test.cpp
@@ -441,7 +441,7 @@
     sp<FakeInputDispatcherPolicy> mFakePolicy;
     sp<InputDispatcher> mDispatcher;
 
-    virtual void SetUp() override {
+    void SetUp() override {
         mFakePolicy = new FakeInputDispatcherPolicy();
         mDispatcher = new InputDispatcher(mFakePolicy);
         mDispatcher->setInputDispatchMode(/*enabled*/ true, /*frozen*/ false);
@@ -449,7 +449,7 @@
         ASSERT_EQ(OK, mDispatcher->start());
     }
 
-    virtual void TearDown() override {
+    void TearDown() override {
         ASSERT_EQ(OK, mDispatcher->stop());
         mFakePolicy.clear();
         mDispatcher.clear();
diff --git a/services/inputflinger/tests/LatencyTracker_test.cpp b/services/inputflinger/tests/LatencyTracker_test.cpp
new file mode 100644
index 0000000..e7e1937
--- /dev/null
+++ b/services/inputflinger/tests/LatencyTracker_test.cpp
@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "../dispatcher/LatencyTracker.h"
+
+#include <binder/Binder.h>
+#include <gtest/gtest.h>
+#include <inttypes.h>
+#include <log/log.h>
+
+#define TAG "LatencyTracker_test"
+
+using android::inputdispatcher::InputEventTimeline;
+using android::inputdispatcher::LatencyTracker;
+
+namespace android::inputdispatcher {
+
+InputEventTimeline getTestTimeline() {
+    InputEventTimeline t(
+            /*isDown*/ true,
+            /*eventTime*/ 2,
+            /*readTime*/ 3);
+    ConnectionTimeline expectedCT(/*deliveryTime*/ 6, /* consumeTime*/ 7, /*finishTime*/ 8);
+    std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline;
+    graphicsTimeline[GraphicsTimeline::GPU_COMPLETED_TIME] = 9;
+    graphicsTimeline[GraphicsTimeline::PRESENT_TIME] = 10;
+    expectedCT.setGraphicsTimeline(std::move(graphicsTimeline));
+    t.connectionTimelines.emplace(new BBinder(), std::move(expectedCT));
+    return t;
+}
+
+// --- LatencyTrackerTest ---
+class LatencyTrackerTest : public testing::Test, public InputEventTimelineProcessor {
+protected:
+    std::unique_ptr<LatencyTracker> mTracker;
+    sp<IBinder> connection1;
+    sp<IBinder> connection2;
+
+    void SetUp() override {
+        connection1 = new BBinder();
+        connection2 = new BBinder();
+
+        mTracker = std::make_unique<LatencyTracker>(this);
+    }
+    void TearDown() override {}
+
+    void assertReceivedTimeline(const InputEventTimeline& timeline);
+    /**
+     * Timelines can be received in any order (order is not guaranteed). So if we are expecting more
+     * than 1 timeline, use this function to check that the set of received timelines matches
+     * what we expected.
+     */
+    void assertReceivedTimelines(const std::vector<InputEventTimeline>& timelines);
+
+private:
+    void processTimeline(const InputEventTimeline& timeline) override {
+        mReceivedTimelines.push_back(timeline);
+    }
+    std::deque<InputEventTimeline> mReceivedTimelines;
+};
+
+void LatencyTrackerTest::assertReceivedTimeline(const InputEventTimeline& timeline) {
+    mTracker->reportNow();
+    ASSERT_FALSE(mReceivedTimelines.empty());
+    const InputEventTimeline& t = mReceivedTimelines.front();
+    ASSERT_EQ(timeline, t);
+    mReceivedTimelines.pop_front();
+}
+
+/**
+ * We are essentially comparing two multisets, but without constructing them.
+ * This comparison is inefficient, but it avoids having to construct a set, and also avoids the
+ * declaration of copy constructor for ConnectionTimeline.
+ * We ensure that collections A and B have the same size, that for every element in A, there is an
+ * equal element in B, and for every element in B there is an equal element in A.
+ */
+void LatencyTrackerTest::assertReceivedTimelines(const std::vector<InputEventTimeline>& timelines) {
+    mTracker->reportNow();
+    ASSERT_EQ(timelines.size(), mReceivedTimelines.size());
+    for (const InputEventTimeline& expectedTimeline : timelines) {
+        bool found = false;
+        for (const InputEventTimeline& receivedTimeline : mReceivedTimelines) {
+            if (receivedTimeline == expectedTimeline) {
+                found = true;
+                break;
+            }
+        }
+        ASSERT_TRUE(found) << "Could not find expected timeline with eventTime="
+                           << expectedTimeline.eventTime;
+    }
+    for (const InputEventTimeline& receivedTimeline : mReceivedTimelines) {
+        bool found = false;
+        for (const InputEventTimeline& expectedTimeline : timelines) {
+            if (receivedTimeline == expectedTimeline) {
+                found = true;
+                break;
+            }
+        }
+        ASSERT_TRUE(found) << "Could not find received timeline with eventTime="
+                           << receivedTimeline.eventTime;
+    }
+    mReceivedTimelines.clear();
+}
+
+/**
+ * Ensure that calling 'trackListener' in isolation only creates an inputflinger timeline, without
+ * any additional ConnectionTimeline's.
+ */
+TEST_F(LatencyTrackerTest, TrackListener_DoesNotTriggerReporting) {
+    mTracker->trackListener(1 /*inputEventId*/, false /*isDown*/, 2 /*eventTime*/, 3 /*readTime*/);
+    assertReceivedTimeline(InputEventTimeline{false, 2, 3});
+}
+
+/**
+ * A single call to trackFinishedEvent should not cause a timeline to be reported.
+ */
+TEST_F(LatencyTrackerTest, TrackFinishedEvent_DoesNotTriggerReporting) {
+    mTracker->trackFinishedEvent(1 /*inputEventId*/, connection1, 2 /*deliveryTime*/,
+                                 3 /*consumeTime*/, 4 /*finishTime*/);
+    assertReceivedTimelines({});
+}
+
+/**
+ * A single call to trackGraphicsLatency should not cause a timeline to be reported.
+ */
+TEST_F(LatencyTrackerTest, TrackGraphicsLatency_DoesNotTriggerReporting) {
+    std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline;
+    graphicsTimeline[GraphicsTimeline::GPU_COMPLETED_TIME] = 2;
+    graphicsTimeline[GraphicsTimeline::PRESENT_TIME] = 3;
+    mTracker->trackGraphicsLatency(1 /*inputEventId*/, connection2, graphicsTimeline);
+    assertReceivedTimelines({});
+}
+
+TEST_F(LatencyTrackerTest, TrackAllParameters_ReportsFullTimeline) {
+    constexpr int32_t inputEventId = 1;
+    InputEventTimeline expected = getTestTimeline();
+
+    const auto& [connectionToken, expectedCT] = *expected.connectionTimelines.begin();
+
+    mTracker->trackListener(inputEventId, expected.isDown, expected.eventTime, expected.readTime);
+    mTracker->trackFinishedEvent(inputEventId, connectionToken, expectedCT.deliveryTime,
+                                 expectedCT.consumeTime, expectedCT.finishTime);
+    mTracker->trackGraphicsLatency(inputEventId, connectionToken, expectedCT.graphicsTimeline);
+
+    assertReceivedTimeline(expected);
+}
+
+TEST_F(LatencyTrackerTest, MultipleEvents_AreReportedConsistently) {
+    constexpr int32_t inputEventId1 = 1;
+    InputEventTimeline timeline1(
+            /*isDown*/ true,
+            /*eventTime*/ 2,
+            /*readTime*/ 3);
+    timeline1.connectionTimelines.emplace(connection1,
+                                          ConnectionTimeline(/*deliveryTime*/ 6, /*consumeTime*/ 7,
+                                                             /*finishTime*/ 8));
+    ConnectionTimeline& connectionTimeline1 = timeline1.connectionTimelines.begin()->second;
+    std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline1;
+    graphicsTimeline1[GraphicsTimeline::GPU_COMPLETED_TIME] = 9;
+    graphicsTimeline1[GraphicsTimeline::PRESENT_TIME] = 10;
+    connectionTimeline1.setGraphicsTimeline(std::move(graphicsTimeline1));
+
+    constexpr int32_t inputEventId2 = 10;
+    InputEventTimeline timeline2(
+            /*isDown*/ false,
+            /*eventTime*/ 20,
+            /*readTime*/ 30);
+    timeline2.connectionTimelines.emplace(connection2,
+                                          ConnectionTimeline(/*deliveryTime*/ 60,
+                                                             /*consumeTime*/ 70,
+                                                             /*finishTime*/ 80));
+    ConnectionTimeline& connectionTimeline2 = timeline2.connectionTimelines.begin()->second;
+    std::array<nsecs_t, GraphicsTimeline::SIZE> graphicsTimeline2;
+    graphicsTimeline2[GraphicsTimeline::GPU_COMPLETED_TIME] = 90;
+    graphicsTimeline2[GraphicsTimeline::PRESENT_TIME] = 100;
+    connectionTimeline2.setGraphicsTimeline(std::move(graphicsTimeline2));
+
+    // Start processing first event
+    mTracker->trackListener(inputEventId1, timeline1.isDown, timeline1.eventTime,
+                            timeline1.readTime);
+    // Start processing second event
+    mTracker->trackListener(inputEventId2, timeline2.isDown, timeline2.eventTime,
+                            timeline2.readTime);
+    mTracker->trackFinishedEvent(inputEventId1, connection1, connectionTimeline1.deliveryTime,
+                                 connectionTimeline1.consumeTime, connectionTimeline1.finishTime);
+
+    mTracker->trackFinishedEvent(inputEventId2, connection2, connectionTimeline2.deliveryTime,
+                                 connectionTimeline2.consumeTime, connectionTimeline2.finishTime);
+    mTracker->trackGraphicsLatency(inputEventId1, connection1,
+                                   connectionTimeline1.graphicsTimeline);
+    mTracker->trackGraphicsLatency(inputEventId2, connection2,
+                                   connectionTimeline2.graphicsTimeline);
+    // Now both events should be completed
+    assertReceivedTimelines({timeline1, timeline2});
+}
+
+/**
+ * Check that LatencyTracker consistently tracks events even if there are many incomplete events.
+ */
+TEST_F(LatencyTrackerTest, IncompleteEvents_AreHandledConsistently) {
+    InputEventTimeline timeline = getTestTimeline();
+    std::vector<InputEventTimeline> expectedTimelines;
+    const ConnectionTimeline& expectedCT = timeline.connectionTimelines.begin()->second;
+    const sp<IBinder>& token = timeline.connectionTimelines.begin()->first;
+
+    for (size_t i = 1; i <= 100; i++) {
+        mTracker->trackListener(i /*inputEventId*/, timeline.isDown, timeline.eventTime,
+                                timeline.readTime);
+        expectedTimelines.push_back(
+                InputEventTimeline{timeline.isDown, timeline.eventTime, timeline.readTime});
+    }
+    // Now, complete the first event that was sent.
+    mTracker->trackFinishedEvent(1 /*inputEventId*/, token, expectedCT.deliveryTime,
+                                 expectedCT.consumeTime, expectedCT.finishTime);
+    mTracker->trackGraphicsLatency(1 /*inputEventId*/, token, expectedCT.graphicsTimeline);
+
+    expectedTimelines[0].connectionTimelines.emplace(token, std::move(expectedCT));
+    assertReceivedTimelines(expectedTimelines);
+}
+
+/**
+ * For simplicity of the implementation, LatencyTracker only starts tracking an event when
+ * 'trackListener' is invoked.
+ * Both 'trackFinishedEvent' and 'trackGraphicsLatency' should not start a new event.
+ * If they are received before 'trackListener' (which should not be possible), they are ignored.
+ */
+TEST_F(LatencyTrackerTest, EventsAreTracked_WhenTrackListenerIsCalledFirst) {
+    constexpr int32_t inputEventId = 1;
+    InputEventTimeline expected = getTestTimeline();
+    const ConnectionTimeline& expectedCT = expected.connectionTimelines.begin()->second;
+    mTracker->trackFinishedEvent(inputEventId, connection1, expectedCT.deliveryTime,
+                                 expectedCT.consumeTime, expectedCT.finishTime);
+    mTracker->trackGraphicsLatency(inputEventId, connection1, expectedCT.graphicsTimeline);
+
+    mTracker->trackListener(inputEventId, expected.isDown, expected.eventTime, expected.readTime);
+    assertReceivedTimeline(
+            InputEventTimeline{expected.isDown, expected.eventTime, expected.readTime});
+}
+
+} // namespace android::inputdispatcher