diff --git a/framework-t/Android.bp b/framework-t/Android.bp
index a6700e5..b5aedeb 100644
--- a/framework-t/Android.bp
+++ b/framework-t/Android.bp
@@ -87,6 +87,7 @@
 
         // Tests using hidden APIs
         "//cts/tests/netlegacy22.api",
+        "//cts/tests/tests/app.usage", // NetworkUsageStatsTest
         "//external/sl4a:__subpackages__",
         "//frameworks/libs/net/common/testutils",
         "//frameworks/libs/net/common/tests:__subpackages__",
diff --git a/framework/Android.bp b/framework/Android.bp
index 1545264..d3e46fa 100644
--- a/framework/Android.bp
+++ b/framework/Android.bp
@@ -128,6 +128,7 @@
 
         // Tests using hidden APIs
         "//cts/tests/netlegacy22.api",
+        "//cts/tests/tests/app.usage", // NetworkUsageStatsTest
         "//external/sl4a:__subpackages__",
         "//frameworks/base/packages/Connectivity/tests:__subpackages__",
         "//frameworks/libs/net/common/testutils",
diff --git a/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java b/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java
new file mode 100644
index 0000000..147fca9
--- /dev/null
+++ b/tests/cts/net/src/android/net/cts/NetworkStatsManagerTest.java
@@ -0,0 +1,878 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+package android.net.cts;
+
+import static android.app.usage.NetworkStats.Bucket.DEFAULT_NETWORK_ALL;
+import static android.app.usage.NetworkStats.Bucket.DEFAULT_NETWORK_NO;
+import static android.app.usage.NetworkStats.Bucket.DEFAULT_NETWORK_YES;
+import static android.app.usage.NetworkStats.Bucket.METERED_ALL;
+import static android.app.usage.NetworkStats.Bucket.METERED_NO;
+import static android.app.usage.NetworkStats.Bucket.METERED_YES;
+import static android.app.usage.NetworkStats.Bucket.STATE_ALL;
+import static android.app.usage.NetworkStats.Bucket.STATE_DEFAULT;
+import static android.app.usage.NetworkStats.Bucket.STATE_FOREGROUND;
+import static android.app.usage.NetworkStats.Bucket.TAG_NONE;
+import static android.app.usage.NetworkStats.Bucket.UID_ALL;
+
+import android.app.AppOpsManager;
+import android.app.usage.NetworkStats;
+import android.app.usage.NetworkStatsManager;
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.net.ConnectivityManager;
+import android.net.Network;
+import android.net.NetworkCapabilities;
+import android.net.NetworkInfo;
+import android.net.NetworkRequest;
+import android.net.TrafficStats;
+import android.os.Handler;
+import android.os.HandlerThread;
+import android.os.Process;
+import android.os.RemoteException;
+import android.os.SystemClock;
+import android.platform.test.annotations.AppModeFull;
+import android.telephony.TelephonyManager;
+import android.test.InstrumentationTestCase;
+import android.util.Log;
+
+import com.android.compatibility.common.util.ShellIdentityUtils;
+import com.android.compatibility.common.util.SystemUtil;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.URL;
+import java.net.UnknownHostException;
+import java.text.MessageFormat;
+import java.util.ArrayList;
+
+public class NetworkStatsManagerTest extends InstrumentationTestCase {
+    private static final String LOG_TAG = "NetworkStatsManagerTest";
+    private static final String APPOPS_SET_SHELL_COMMAND = "appops set {0} {1} {2}";
+    private static final String APPOPS_GET_SHELL_COMMAND = "appops get {0} {1}";
+
+    private static final long MINUTE = 1000 * 60;
+    private static final int TIMEOUT_MILLIS = 15000;
+
+    private static final String CHECK_CONNECTIVITY_URL = "http://www.265.com/";
+    private static final int HOST_RESOLUTION_RETRIES = 4;
+    private static final int HOST_RESOLUTION_INTERVAL_MS = 500;
+
+    private static final int NETWORK_TAG = 0xf00d;
+    private static final long THRESHOLD_BYTES = 2 * 1024 * 1024;  // 2 MB
+
+    private abstract class NetworkInterfaceToTest {
+        private boolean mMetered;
+        private boolean mIsDefault;
+
+        abstract int getNetworkType();
+        abstract int getTransportType();
+
+        public boolean getMetered() {
+            return mMetered;
+        }
+
+        public void setMetered(boolean metered) {
+            this.mMetered = metered;
+        }
+
+        public boolean getIsDefault() {
+            return mIsDefault;
+        }
+
+        public void setIsDefault(boolean isDefault) {
+            mIsDefault = isDefault;
+        }
+
+        abstract String getSystemFeature();
+        abstract String getErrorMessage();
+    }
+
+    private final NetworkInterfaceToTest[] mNetworkInterfacesToTest =
+            new NetworkInterfaceToTest[] {
+                    new NetworkInterfaceToTest() {
+                        @Override
+                        public int getNetworkType() {
+                            return ConnectivityManager.TYPE_WIFI;
+                        }
+
+                        @Override
+                        public int getTransportType() {
+                            return NetworkCapabilities.TRANSPORT_WIFI;
+                        }
+
+                        @Override
+                        public String getSystemFeature() {
+                            return PackageManager.FEATURE_WIFI;
+                        }
+
+                        @Override
+                        public String getErrorMessage() {
+                            return " Please make sure you are connected to a WiFi access point.";
+                        }
+                    },
+                    new NetworkInterfaceToTest() {
+                        @Override
+                        public int getNetworkType() {
+                            return ConnectivityManager.TYPE_MOBILE;
+                        }
+
+                        @Override
+                        public int getTransportType() {
+                            return NetworkCapabilities.TRANSPORT_CELLULAR;
+                        }
+
+                        @Override
+                        public String getSystemFeature() {
+                            return PackageManager.FEATURE_TELEPHONY;
+                        }
+
+                        @Override
+                        public String getErrorMessage() {
+                            return " Please make sure you have added a SIM card with data plan to"
+                                    + " your phone, have enabled data over cellular and in case of"
+                                    + " dual SIM devices, have selected the right SIM "
+                                    + "for data connection.";
+                        }
+                    }
+            };
+
+    private String mPkg;
+    private NetworkStatsManager mNsm;
+    private ConnectivityManager mCm;
+    private PackageManager mPm;
+    private long mStartTime;
+    private long mEndTime;
+
+    private long mBytesRead;
+    private String mWriteSettingsMode;
+    private String mUsageStatsMode;
+
+    private void exerciseRemoteHost(Network network, URL url) throws Exception {
+        NetworkInfo networkInfo = mCm.getNetworkInfo(network);
+        if (networkInfo == null) {
+            Log.w(LOG_TAG, "Network info is null");
+        } else {
+            Log.w(LOG_TAG, "Network: " + networkInfo.toString());
+        }
+        InputStreamReader in = null;
+        HttpURLConnection urlc = null;
+        String originalKeepAlive = System.getProperty("http.keepAlive");
+        System.setProperty("http.keepAlive", "false");
+        try {
+            TrafficStats.setThreadStatsTag(NETWORK_TAG);
+            urlc = (HttpURLConnection) network.openConnection(url);
+            urlc.setConnectTimeout(TIMEOUT_MILLIS);
+            urlc.setUseCaches(false);
+            // Disable compression so we generate enough traffic that assertWithinPercentage will
+            // not be affected by the small amount of traffic (5-10kB) sent by the test harness.
+            urlc.setRequestProperty("Accept-Encoding", "identity");
+            urlc.connect();
+            boolean ping = urlc.getResponseCode() == 200;
+            if (ping) {
+                in = new InputStreamReader(
+                        (InputStream) urlc.getContent());
+
+                mBytesRead = 0;
+                while (in.read() != -1) ++mBytesRead;
+            }
+        } catch (Exception e) {
+            Log.i(LOG_TAG, "Badness during exercising remote server: " + e);
+        } finally {
+            TrafficStats.clearThreadStatsTag();
+            if (in != null) {
+                try {
+                    in.close();
+                } catch (IOException e) {
+                    // don't care
+                }
+            }
+            if (urlc != null) {
+                urlc.disconnect();
+            }
+            if (originalKeepAlive == null) {
+                System.clearProperty("http.keepAlive");
+            } else {
+                System.setProperty("http.keepAlive", originalKeepAlive);
+            }
+        }
+    }
+
+    @Override
+    protected void setUp() throws Exception {
+        super.setUp();
+        mNsm = (NetworkStatsManager) getInstrumentation().getContext()
+                .getSystemService(Context.NETWORK_STATS_SERVICE);
+        mNsm.setPollForce(true);
+
+        mCm = (ConnectivityManager) getInstrumentation().getContext()
+                .getSystemService(Context.CONNECTIVITY_SERVICE);
+
+        mPm = getInstrumentation().getContext().getPackageManager();
+
+        mPkg = getInstrumentation().getContext().getPackageName();
+
+        mWriteSettingsMode = getAppOpsMode(AppOpsManager.OPSTR_WRITE_SETTINGS);
+        setAppOpsMode(AppOpsManager.OPSTR_WRITE_SETTINGS, "allow");
+        mUsageStatsMode = getAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS);
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+        if (mWriteSettingsMode != null) {
+            setAppOpsMode(AppOpsManager.OPSTR_WRITE_SETTINGS, mWriteSettingsMode);
+        }
+        if (mUsageStatsMode != null) {
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, mUsageStatsMode);
+        }
+        super.tearDown();
+    }
+
+    private void setAppOpsMode(String appop, String mode) throws Exception {
+        final String command = MessageFormat.format(APPOPS_SET_SHELL_COMMAND, mPkg, appop, mode);
+        SystemUtil.runShellCommand(command);
+    }
+
+    private String getAppOpsMode(String appop) throws Exception {
+        final String command = MessageFormat.format(APPOPS_GET_SHELL_COMMAND, mPkg, appop);
+        String result = SystemUtil.runShellCommand(command);
+        if (result == null) {
+            Log.w(LOG_TAG, "App op " + appop + " could not be read.");
+        }
+        return result;
+    }
+
+    private boolean isInForeground() throws IOException {
+        String result = SystemUtil.runShellCommand(getInstrumentation(),
+                "cmd activity get-uid-state " + Process.myUid());
+        return result.contains("FOREGROUND");
+    }
+
+    private class NetworkCallback extends ConnectivityManager.NetworkCallback {
+        private long mTolerance;
+        private URL mUrl;
+        public boolean success;
+        public boolean metered;
+        public boolean isDefault;
+
+        NetworkCallback(long tolerance, URL url) {
+            mTolerance = tolerance;
+            mUrl = url;
+            success = false;
+            metered = false;
+            isDefault = false;
+        }
+
+        // The test host only has IPv4. So on a dual-stack network where IPv6 connects before IPv4,
+        // we need to wait until IPv4 is available or the test will spuriously fail.
+        private void waitForHostResolution(Network network) {
+            for (int i = 0; i < HOST_RESOLUTION_RETRIES; i++) {
+                try {
+                    network.getAllByName(mUrl.getHost());
+                    return;
+                } catch (UnknownHostException e) {
+                    SystemClock.sleep(HOST_RESOLUTION_INTERVAL_MS);
+                }
+            }
+            fail(String.format("%s could not be resolved on network %s (%d attempts %dms apart)",
+                    mUrl.getHost(), network, HOST_RESOLUTION_RETRIES, HOST_RESOLUTION_INTERVAL_MS));
+        }
+
+        @Override
+        public void onAvailable(Network network) {
+            try {
+                mStartTime = System.currentTimeMillis() - mTolerance;
+                isDefault = network.equals(mCm.getActiveNetwork());
+                waitForHostResolution(network);
+                exerciseRemoteHost(network, mUrl);
+                mEndTime = System.currentTimeMillis() + mTolerance;
+                success = true;
+                metered = !mCm.getNetworkCapabilities(network)
+                        .hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED);
+                synchronized (NetworkStatsManagerTest.this) {
+                    NetworkStatsManagerTest.this.notify();
+                }
+            } catch (Exception e) {
+                Log.w(LOG_TAG, "exercising remote host failed.", e);
+                success = false;
+            }
+        }
+    }
+
+    private boolean shouldTestThisNetworkType(int networkTypeIndex, final long tolerance)
+            throws Exception {
+        boolean hasFeature = mPm.hasSystemFeature(
+                mNetworkInterfacesToTest[networkTypeIndex].getSystemFeature());
+        if (!hasFeature) {
+            return false;
+        }
+        NetworkCallback callback = new NetworkCallback(tolerance, new URL(CHECK_CONNECTIVITY_URL));
+        mCm.requestNetwork(new NetworkRequest.Builder()
+                .addTransportType(mNetworkInterfacesToTest[networkTypeIndex].getTransportType())
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+                .build(), callback);
+        synchronized (this) {
+            try {
+                wait((int) (TIMEOUT_MILLIS * 1.2));
+            } catch (InterruptedException e) {
+            }
+        }
+        if (callback.success) {
+            mNetworkInterfacesToTest[networkTypeIndex].setMetered(callback.metered);
+            mNetworkInterfacesToTest[networkTypeIndex].setIsDefault(callback.isDefault);
+            return true;
+        }
+
+        // This will always fail at this point as we know 'hasFeature' is true.
+        assertFalse(mNetworkInterfacesToTest[networkTypeIndex].getSystemFeature()
+                + " is a reported system feature, "
+                + "however no corresponding connected network interface was found or the attempt "
+                + "to connect has timed out (timeout = " + TIMEOUT_MILLIS + "ms)."
+                + mNetworkInterfacesToTest[networkTypeIndex].getErrorMessage(), hasFeature);
+        return false;
+    }
+
+    private String getSubscriberId(int networkIndex) {
+        int networkType = mNetworkInterfacesToTest[networkIndex].getNetworkType();
+        if (ConnectivityManager.TYPE_MOBILE == networkType) {
+            TelephonyManager tm = (TelephonyManager) getInstrumentation().getContext()
+                    .getSystemService(Context.TELEPHONY_SERVICE);
+            return ShellIdentityUtils.invokeMethodWithShellPermissions(tm,
+                    (telephonyManager) -> telephonyManager.getSubscriberId());
+        }
+        return "";
+    }
+
+    @AppModeFull
+    public void testDeviceSummary() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            if (!shouldTestThisNetworkType(i, MINUTE / 2)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats.Bucket bucket = null;
+            try {
+                bucket = mNsm.querySummaryForDevice(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+            } catch (RemoteException | SecurityException e) {
+                fail("testDeviceSummary fails with exception: " + e.toString());
+            }
+            assertNotNull(bucket);
+            assertTimestamps(bucket);
+            assertEquals(bucket.getState(), STATE_ALL);
+            assertEquals(bucket.getUid(), UID_ALL);
+            assertEquals(bucket.getMetered(), METERED_ALL);
+            assertEquals(bucket.getDefaultNetworkStatus(), DEFAULT_NETWORK_ALL);
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                bucket = mNsm.querySummaryForDevice(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+                fail("negative testDeviceSummary fails: no exception thrown.");
+            } catch (RemoteException e) {
+                fail("testDeviceSummary fails with exception: " + e.toString());
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    @AppModeFull
+    public void testUserSummary() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            if (!shouldTestThisNetworkType(i, MINUTE / 2)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats.Bucket bucket = null;
+            try {
+                bucket = mNsm.querySummaryForUser(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+            } catch (RemoteException | SecurityException e) {
+                fail("testUserSummary fails with exception: " + e.toString());
+            }
+            assertNotNull(bucket);
+            assertTimestamps(bucket);
+            assertEquals(bucket.getState(), STATE_ALL);
+            assertEquals(bucket.getUid(), UID_ALL);
+            assertEquals(bucket.getMetered(), METERED_ALL);
+            assertEquals(bucket.getDefaultNetworkStatus(), DEFAULT_NETWORK_ALL);
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                bucket = mNsm.querySummaryForUser(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+                fail("negative testUserSummary fails: no exception thrown.");
+            } catch (RemoteException e) {
+                fail("testUserSummary fails with exception: " + e.toString());
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    @AppModeFull
+    public void testAppSummary() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            // Use tolerance value that large enough to make sure stats of at
+            // least one bucket is included. However, this is possible that
+            // the test will see data of different app but with the same UID
+            // that created before testing.
+            // TODO: Consider query stats before testing and use the difference to verify.
+            if (!shouldTestThisNetworkType(i, MINUTE * 120)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats result = null;
+            try {
+                result = mNsm.querySummary(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+                assertNotNull(result);
+                NetworkStats.Bucket bucket = new NetworkStats.Bucket();
+                long totalTxPackets = 0;
+                long totalRxPackets = 0;
+                long totalTxBytes = 0;
+                long totalRxBytes = 0;
+                boolean hasCorrectMetering = false;
+                boolean hasCorrectDefaultStatus = false;
+                int expectedMetering = mNetworkInterfacesToTest[i].getMetered()
+                        ? METERED_YES : METERED_NO;
+                int expectedDefaultStatus = mNetworkInterfacesToTest[i].getIsDefault()
+                        ? DEFAULT_NETWORK_YES : DEFAULT_NETWORK_NO;
+                while (result.hasNextBucket()) {
+                    assertTrue(result.getNextBucket(bucket));
+                    assertTimestamps(bucket);
+                    hasCorrectMetering |= bucket.getMetered() == expectedMetering;
+                    if (bucket.getUid() == Process.myUid()) {
+                        totalTxPackets += bucket.getTxPackets();
+                        totalRxPackets += bucket.getRxPackets();
+                        totalTxBytes += bucket.getTxBytes();
+                        totalRxBytes += bucket.getRxBytes();
+                        hasCorrectDefaultStatus |=
+                                bucket.getDefaultNetworkStatus() == expectedDefaultStatus;
+                    }
+                }
+                assertFalse(result.getNextBucket(bucket));
+                assertTrue("Incorrect metering for NetworkType: "
+                        + mNetworkInterfacesToTest[i].getNetworkType(), hasCorrectMetering);
+                assertTrue("Incorrect isDefault for NetworkType: "
+                        + mNetworkInterfacesToTest[i].getNetworkType(), hasCorrectDefaultStatus);
+                assertTrue("No Rx bytes usage for uid " + Process.myUid(), totalRxBytes > 0);
+                assertTrue("No Rx packets usage for uid " + Process.myUid(), totalRxPackets > 0);
+                assertTrue("No Tx bytes usage for uid " + Process.myUid(), totalTxBytes > 0);
+                assertTrue("No Tx packets usage for uid " + Process.myUid(), totalTxPackets > 0);
+            } finally {
+                if (result != null) {
+                    result.close();
+                }
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                result = mNsm.querySummary(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+                fail("negative testAppSummary fails: no exception thrown.");
+            } catch (RemoteException e) {
+                fail("testAppSummary fails with exception: " + e.toString());
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    @AppModeFull
+    public void testAppDetails() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            // Relatively large tolerance to accommodate for history bucket size.
+            if (!shouldTestThisNetworkType(i, MINUTE * 120)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats result = null;
+            try {
+                result = mNsm.queryDetails(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+                long totalBytesWithSubscriberId = getTotalAndAssertNotEmpty(result);
+
+                // Test without filtering by subscriberId
+                result = mNsm.queryDetails(
+                        mNetworkInterfacesToTest[i].getNetworkType(), null,
+                        mStartTime, mEndTime);
+
+                assertTrue("More bytes with subscriberId filter than without.",
+                        getTotalAndAssertNotEmpty(result) >= totalBytesWithSubscriberId);
+            } catch (RemoteException | SecurityException e) {
+                fail("testAppDetails fails with exception: " + e.toString());
+            } finally {
+                if (result != null) {
+                    result.close();
+                }
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                result = mNsm.queryDetails(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime);
+                fail("negative testAppDetails fails: no exception thrown.");
+            } catch (RemoteException e) {
+                fail("testAppDetails fails with exception: " + e.toString());
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    @AppModeFull
+    public void testUidDetails() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            // Relatively large tolerance to accommodate for history bucket size.
+            if (!shouldTestThisNetworkType(i, MINUTE * 120)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats result = null;
+            try {
+                result = mNsm.queryDetailsForUid(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime, Process.myUid());
+                assertNotNull(result);
+                NetworkStats.Bucket bucket = new NetworkStats.Bucket();
+                long totalTxPackets = 0;
+                long totalRxPackets = 0;
+                long totalTxBytes = 0;
+                long totalRxBytes = 0;
+                while (result.hasNextBucket()) {
+                    assertTrue(result.getNextBucket(bucket));
+                    assertTimestamps(bucket);
+                    assertEquals(bucket.getState(), STATE_ALL);
+                    assertEquals(bucket.getMetered(), METERED_ALL);
+                    assertEquals(bucket.getDefaultNetworkStatus(), DEFAULT_NETWORK_ALL);
+                    assertEquals(bucket.getUid(), Process.myUid());
+                    totalTxPackets += bucket.getTxPackets();
+                    totalRxPackets += bucket.getRxPackets();
+                    totalTxBytes += bucket.getTxBytes();
+                    totalRxBytes += bucket.getRxBytes();
+                }
+                assertFalse(result.getNextBucket(bucket));
+                assertTrue("No Rx bytes usage for uid " + Process.myUid(), totalRxBytes > 0);
+                assertTrue("No Rx packets usage for uid " + Process.myUid(), totalRxPackets > 0);
+                assertTrue("No Tx bytes usage for uid " + Process.myUid(), totalTxBytes > 0);
+                assertTrue("No Tx packets usage for uid " + Process.myUid(), totalTxPackets > 0);
+            } finally {
+                if (result != null) {
+                    result.close();
+                }
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                result = mNsm.queryDetailsForUid(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime, Process.myUid());
+                fail("negative testUidDetails fails: no exception thrown.");
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    @AppModeFull
+    public void testTagDetails() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            // Relatively large tolerance to accommodate for history bucket size.
+            if (!shouldTestThisNetworkType(i, MINUTE * 120)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats result = null;
+            try {
+                result = mNsm.queryDetailsForUidTag(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime, Process.myUid(), NETWORK_TAG);
+                assertNotNull(result);
+                NetworkStats.Bucket bucket = new NetworkStats.Bucket();
+                long totalTxPackets = 0;
+                long totalRxPackets = 0;
+                long totalTxBytes = 0;
+                long totalRxBytes = 0;
+                while (result.hasNextBucket()) {
+                    assertTrue(result.getNextBucket(bucket));
+                    assertTimestamps(bucket);
+                    assertEquals(bucket.getState(), STATE_ALL);
+                    assertEquals(bucket.getMetered(), METERED_ALL);
+                    assertEquals(bucket.getDefaultNetworkStatus(), DEFAULT_NETWORK_ALL);
+                    assertEquals(bucket.getUid(), Process.myUid());
+                    if (bucket.getTag() == NETWORK_TAG) {
+                        totalTxPackets += bucket.getTxPackets();
+                        totalRxPackets += bucket.getRxPackets();
+                        totalTxBytes += bucket.getTxBytes();
+                        totalRxBytes += bucket.getRxBytes();
+                    }
+                }
+                assertTrue("No Rx bytes tagged with 0x" + Integer.toHexString(NETWORK_TAG)
+                        + " for uid " + Process.myUid(), totalRxBytes > 0);
+                assertTrue("No Rx packets tagged with 0x" + Integer.toHexString(NETWORK_TAG)
+                        + " for uid " + Process.myUid(), totalRxPackets > 0);
+                assertTrue("No Tx bytes tagged with 0x" + Integer.toHexString(NETWORK_TAG)
+                        + " for uid " + Process.myUid(), totalTxBytes > 0);
+                assertTrue("No Tx packets tagged with 0x" + Integer.toHexString(NETWORK_TAG)
+                        + " for uid " + Process.myUid(), totalTxPackets > 0);
+            } finally {
+                if (result != null) {
+                    result.close();
+                }
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                result = mNsm.queryDetailsForUidTag(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime, Process.myUid(), NETWORK_TAG);
+                fail("negative testUidDetails fails: no exception thrown.");
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    class QueryResult {
+        public final int tag;
+        public final int state;
+        public final long total;
+
+        QueryResult(int tag, int state, NetworkStats stats) {
+            this.tag = tag;
+            this.state = state;
+            total = getTotalAndAssertNotEmpty(stats, tag, state);
+        }
+
+        public String toString() {
+            return String.format("QueryResult(tag=%s state=%s total=%d)",
+                    tagToString(tag), stateToString(state), total);
+        }
+    }
+
+    private NetworkStats getNetworkStatsForTagState(int i, int tag, int state) {
+        return mNsm.queryDetailsForUidTagState(
+                mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                mStartTime, mEndTime, Process.myUid(), tag, state);
+    }
+
+    private void assertWithinPercentage(String msg, long expected, long actual, int percentage) {
+        long lowerBound = expected * (100 - percentage) / 100;
+        long upperBound = expected * (100 + percentage) / 100;
+        msg = String.format("%s: %d not within %d%% of %d", msg, actual, percentage, expected);
+        assertTrue(msg, lowerBound <= actual);
+        assertTrue(msg, upperBound >= actual);
+    }
+
+    private void assertAlmostNoUnexpectedTraffic(NetworkStats result, int expectedTag,
+            int expectedState, long maxUnexpected) {
+        long total = 0;
+        NetworkStats.Bucket bucket = new NetworkStats.Bucket();
+        while (result.hasNextBucket()) {
+            assertTrue(result.getNextBucket(bucket));
+            total += bucket.getRxBytes() + bucket.getTxBytes();
+        }
+        if (total <= maxUnexpected) return;
+
+        fail(String.format("More than %d bytes of traffic when querying for "
+                + "tag %s state %s. Last bucket: uid=%d tag=%s state=%s bytes=%d/%d",
+                maxUnexpected, tagToString(expectedTag), stateToString(expectedState),
+                bucket.getUid(), tagToString(bucket.getTag()), stateToString(bucket.getState()),
+                bucket.getRxBytes(), bucket.getTxBytes()));
+    }
+
+    @AppModeFull
+    public void testUidTagStateDetails() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            // Relatively large tolerance to accommodate for history bucket size.
+            if (!shouldTestThisNetworkType(i, MINUTE * 120)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+            NetworkStats result = null;
+            try {
+                int currentState = isInForeground() ? STATE_FOREGROUND : STATE_DEFAULT;
+                int otherState = (currentState == STATE_DEFAULT) ? STATE_FOREGROUND : STATE_DEFAULT;
+
+                int[] tagsWithTraffic = {NETWORK_TAG, TAG_NONE};
+                int[] statesWithTraffic = {currentState, STATE_ALL};
+                ArrayList<QueryResult> resultsWithTraffic = new ArrayList<>();
+
+                int[] statesWithNoTraffic = {otherState};
+                int[] tagsWithNoTraffic = {NETWORK_TAG + 1};
+                ArrayList<QueryResult> resultsWithNoTraffic = new ArrayList<>();
+
+                // Expect to see traffic when querying for any combination of a tag in
+                // tagsWithTraffic and a state in statesWithTraffic.
+                for (int tag : tagsWithTraffic) {
+                    for (int state : statesWithTraffic) {
+                        result = getNetworkStatsForTagState(i, tag, state);
+                        resultsWithTraffic.add(new QueryResult(tag, state, result));
+                        result.close();
+                        result = null;
+                    }
+                }
+
+                // Expect that the results are within a few percentage points of each other.
+                // This is ensures that FIN retransmits after the transfer is complete don't cause
+                // the test to be flaky. The test URL currently returns just over 100k so this
+                // should not be too noisy. It also ensures that the traffic sent by the test
+                // harness, which is untagged, won't cause a failure.
+                long firstTotal = resultsWithTraffic.get(0).total;
+                for (QueryResult queryResult : resultsWithTraffic) {
+                    assertWithinPercentage(queryResult + "", firstTotal, queryResult.total, 10);
+                }
+
+                // Expect to see no traffic when querying for any tag in tagsWithNoTraffic or any
+                // state in statesWithNoTraffic.
+                for (int tag : tagsWithNoTraffic) {
+                    for (int state : statesWithTraffic) {
+                        result = getNetworkStatsForTagState(i, tag, state);
+                        assertAlmostNoUnexpectedTraffic(result, tag, state, firstTotal / 100);
+                        result.close();
+                        result = null;
+                    }
+                }
+                for (int tag : tagsWithTraffic) {
+                    for (int state : statesWithNoTraffic) {
+                        result = getNetworkStatsForTagState(i, tag, state);
+                        assertAlmostNoUnexpectedTraffic(result, tag, state, firstTotal / 100);
+                        result.close();
+                        result = null;
+                    }
+                }
+            } finally {
+                if (result != null) {
+                    result.close();
+                }
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "deny");
+            try {
+                result = mNsm.queryDetailsForUidTag(
+                        mNetworkInterfacesToTest[i].getNetworkType(), getSubscriberId(i),
+                        mStartTime, mEndTime, Process.myUid(), NETWORK_TAG);
+                fail("negative testUidDetails fails: no exception thrown.");
+            } catch (SecurityException e) {
+                // expected outcome
+            }
+        }
+    }
+
+    @AppModeFull
+    public void testCallback() throws Exception {
+        for (int i = 0; i < mNetworkInterfacesToTest.length; ++i) {
+            // Relatively large tolerance to accommodate for history bucket size.
+            if (!shouldTestThisNetworkType(i, MINUTE / 2)) {
+                continue;
+            }
+            setAppOpsMode(AppOpsManager.OPSTR_GET_USAGE_STATS, "allow");
+
+            TestUsageCallback usageCallback = new TestUsageCallback();
+            HandlerThread thread = new HandlerThread("callback-thread");
+            thread.start();
+            Handler handler = new Handler(thread.getLooper());
+            mNsm.registerUsageCallback(mNetworkInterfacesToTest[i].getNetworkType(),
+                    getSubscriberId(i), THRESHOLD_BYTES, usageCallback, handler);
+
+            // TODO: Force traffic and check whether the callback is invoked.
+            // Right now the test only covers whether the callback can be registered, but not
+            // whether it is invoked upon data usage since we don't have a scalable way of
+            // storing files of >2MB in CTS.
+
+            mNsm.unregisterUsageCallback(usageCallback);
+        }
+    }
+
+    private String tagToString(Integer tag) {
+        if (tag == null) return "null";
+        switch (tag) {
+            case TAG_NONE:
+                return "TAG_NONE";
+            default:
+                return "0x" + Integer.toHexString(tag);
+        }
+    }
+
+    private String stateToString(Integer state) {
+        if (state == null) return "null";
+        switch (state) {
+            case STATE_ALL:
+                return "STATE_ALL";
+            case STATE_DEFAULT:
+                return "STATE_DEFAULT";
+            case STATE_FOREGROUND:
+                return "STATE_FOREGROUND";
+        }
+        throw new IllegalArgumentException("Unknown state " + state);
+    }
+
+    private long getTotalAndAssertNotEmpty(NetworkStats result, Integer expectedTag,
+            Integer expectedState) {
+        assertTrue(result != null);
+        NetworkStats.Bucket bucket = new NetworkStats.Bucket();
+        long totalTxPackets = 0;
+        long totalRxPackets = 0;
+        long totalTxBytes = 0;
+        long totalRxBytes = 0;
+        while (result.hasNextBucket()) {
+            assertTrue(result.getNextBucket(bucket));
+            assertTimestamps(bucket);
+            if (expectedTag != null) assertEquals(bucket.getTag(), (int) expectedTag);
+            if (expectedState != null) assertEquals(bucket.getState(), (int) expectedState);
+            assertEquals(bucket.getMetered(), METERED_ALL);
+            assertEquals(bucket.getDefaultNetworkStatus(), DEFAULT_NETWORK_ALL);
+            if (bucket.getUid() == Process.myUid()) {
+                totalTxPackets += bucket.getTxPackets();
+                totalRxPackets += bucket.getRxPackets();
+                totalTxBytes += bucket.getTxBytes();
+                totalRxBytes += bucket.getRxBytes();
+            }
+        }
+        assertFalse(result.getNextBucket(bucket));
+        String msg = String.format("uid %d tag %s state %s",
+                Process.myUid(), tagToString(expectedTag), stateToString(expectedState));
+        assertTrue("No Rx bytes usage for " + msg, totalRxBytes > 0);
+        assertTrue("No Rx packets usage for " + msg, totalRxPackets > 0);
+        assertTrue("No Tx bytes usage for " + msg, totalTxBytes > 0);
+        assertTrue("No Tx packets usage for " + msg, totalTxPackets > 0);
+
+        return totalRxBytes + totalTxBytes;
+    }
+
+    private long getTotalAndAssertNotEmpty(NetworkStats result) {
+        return getTotalAndAssertNotEmpty(result, null, STATE_ALL);
+    }
+
+    private void assertTimestamps(final NetworkStats.Bucket bucket) {
+        assertTrue("Start timestamp " + bucket.getStartTimeStamp() + " is less than "
+                + mStartTime, bucket.getStartTimeStamp() >= mStartTime);
+        assertTrue("End timestamp " + bucket.getEndTimeStamp() + " is greater than "
+                + mEndTime, bucket.getEndTimeStamp() <= mEndTime);
+    }
+
+    private static class TestUsageCallback extends NetworkStatsManager.UsageCallback {
+        @Override
+        public void onThresholdReached(int networkType, String subscriberId) {
+            Log.v(LOG_TAG, "Called onThresholdReached for networkType=" + networkType
+                    + " subscriberId=" + subscriberId);
+        }
+    }
+}