diff --git a/core/java/android/net/LinkProperties.java b/core/java/android/net/LinkProperties.java
index 8b0dfc9..31aedad 100644
--- a/core/java/android/net/LinkProperties.java
+++ b/core/java/android/net/LinkProperties.java
@@ -88,6 +88,54 @@
     /**
      * @hide
      */
+    public enum ProvisioningChange {
+        STILL_NOT_PROVISIONED,
+        LOST_PROVISIONING,
+        GAINED_PROVISIONING,
+        STILL_PROVISIONED,
+    }
+
+    /**
+     * Compare the provisioning states of two LinkProperties instances.
+     *
+     * @hide
+     */
+    public static ProvisioningChange compareProvisioning(
+            LinkProperties before, LinkProperties after) {
+        if (before.isProvisioned() && after.isProvisioned()) {
+            // On dualstack networks, DHCPv4 renewals can occasionally fail.
+            // When this happens, IPv6-reachable services continue to function
+            // normally but IPv4-only services (naturally) fail.
+            //
+            // When an application using an IPv4-only service reports a bad
+            // network condition to the framework, attempts to re-validate
+            // the network succeed (since we support IPv6-only networks) and
+            // nothing is changed.
+            //
+            // For users, this is confusing and unexpected behaviour, and is
+            // not necessarily easy to diagnose.  Therefore, we treat changing
+            // from a dualstack network to an IPv6-only network equivalent to
+            // a total loss of provisioning.
+            //
+            // For one such example of this, see b/18867306.
+            //
+            // TODO: Remove this special case altogether.
+            if (before.isIPv4Provisioned() && !after.isIPv4Provisioned()) {
+                return ProvisioningChange.LOST_PROVISIONING;
+            }
+            return ProvisioningChange.STILL_PROVISIONED;
+        } else if (before.isProvisioned() && !after.isProvisioned()) {
+            return ProvisioningChange.LOST_PROVISIONING;
+        } else if (!before.isProvisioned() && after.isProvisioned()) {
+            return ProvisioningChange.GAINED_PROVISIONING;
+        } else {  // !before.isProvisioned() && !after.isProvisioned()
+            return ProvisioningChange.STILL_NOT_PROVISIONED;
+        }
+    }
+
+    /**
+     * @hide
+     */
     public LinkProperties() {
     }
 
@@ -287,6 +335,20 @@
     }
 
     /**
+     * Removes the given {@link InetAddress} from the list of DNS servers.
+     *
+     * @param dnsServer The {@link InetAddress} to remove from the list of DNS servers.
+     * @return true if the DNS server was removed, false if it did not exist.
+     * @hide
+     */
+    public boolean removeDnsServer(InetAddress dnsServer) {
+        if (dnsServer != null) {
+            return mDnses.remove(dnsServer);
+        }
+        return false;
+    }
+
+    /**
      * Replaces the DNS servers in this {@code LinkProperties} with
      * the given {@link Collection} of {@link InetAddress} objects.
      *
@@ -679,8 +741,9 @@
      * This requires an IP address, default route, and DNS server.
      *
      * @return {@code true} if the link is provisioned, {@code false} otherwise.
+     * @hide
      */
-    private boolean hasIPv4() {
+    public boolean isIPv4Provisioned() {
         return (hasIPv4Address() &&
                 hasIPv4DefaultRoute() &&
                 hasIPv4DnsServer());
@@ -691,8 +754,9 @@
      * This requires an IP address, default route, and DNS server.
      *
      * @return {@code true} if the link is provisioned, {@code false} otherwise.
+     * @hide
      */
-    private boolean hasIPv6() {
+    public boolean isIPv6Provisioned() {
         return (hasGlobalIPv6Address() &&
                 hasIPv6DefaultRoute() &&
                 hasIPv6DnsServer());
@@ -706,7 +770,7 @@
      * @hide
      */
     public boolean isProvisioned() {
-        return (hasIPv4() || hasIPv6());
+        return (isIPv4Provisioned() || isIPv6Provisioned());
     }
 
     /**
diff --git a/core/java/android/net/NetworkAgent.java b/core/java/android/net/NetworkAgent.java
index 9c3a623..e6fc1ea 100644
--- a/core/java/android/net/NetworkAgent.java
+++ b/core/java/android/net/NetworkAgent.java
@@ -27,6 +27,7 @@
 import com.android.internal.util.Protocol;
 
 import java.util.ArrayList;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
  * A Utility class for handling for communicating between bearer-specific
@@ -51,6 +52,8 @@
     private final ArrayList<Message>mPreConnectedQueue = new ArrayList<Message>();
     private volatile long mLastBwRefreshTime = 0;
     private static final long BW_REFRESH_MIN_WIN_MS = 500;
+    private boolean mPollLceScheduled = false;
+    private AtomicBoolean mPollLcePending = new AtomicBoolean(false);
 
     private static final int BASE = Protocol.BASE_NETWORK_AGENT;
 
@@ -207,11 +210,23 @@
                 break;
             }
             case CMD_REQUEST_BANDWIDTH_UPDATE: {
+                long currentTimeMs = System.currentTimeMillis();
                 if (VDBG) {
                     log("CMD_REQUEST_BANDWIDTH_UPDATE request received.");
                 }
-                if (System.currentTimeMillis() > (mLastBwRefreshTime + BW_REFRESH_MIN_WIN_MS)) {
-                    pollLceData();
+                if (currentTimeMs >= (mLastBwRefreshTime + BW_REFRESH_MIN_WIN_MS)) {
+                    mPollLceScheduled = false;
+                    if (mPollLcePending.getAndSet(true) == false) {
+                        pollLceData();
+                    }
+                } else {
+                    // deliver the request at a later time rather than discard it completely.
+                    if (!mPollLceScheduled) {
+                        long waitTime = mLastBwRefreshTime + BW_REFRESH_MIN_WIN_MS -
+                                currentTimeMs + 1;
+                        mPollLceScheduled = sendEmptyMessageDelayed(
+                                CMD_REQUEST_BANDWIDTH_UPDATE, waitTime);
+                    }
                 }
                 break;
             }
@@ -260,6 +275,7 @@
      * Called by the bearer code when it has new NetworkCapabilities data.
      */
     public void sendNetworkCapabilities(NetworkCapabilities networkCapabilities) {
+        mPollLcePending.set(false);
         mLastBwRefreshTime = System.currentTimeMillis();
         queueOrSendMessage(EVENT_NETWORK_CAPABILITIES_CHANGED,
                 new NetworkCapabilities(networkCapabilities));
diff --git a/core/java/android/net/NetworkRequest.java b/core/java/android/net/NetworkRequest.java
index 7838b47..e61594c 100644
--- a/core/java/android/net/NetworkRequest.java
+++ b/core/java/android/net/NetworkRequest.java
@@ -115,6 +115,18 @@
         }
 
         /**
+         * Completely clears all the {@code NetworkCapabilities} from this builder instance,
+         * removing even the capabilities that are set by default when the object is constructed.
+         *
+         * @return The builder to facilitate chaining.
+         * @hide
+         */
+        public Builder clearCapabilities() {
+            mNetworkCapabilities.clearAll();
+            return this;
+        }
+
+        /**
          * Adds the given transport requirement to this builder.  These represent
          * the set of allowed transports for the request.  Only networks using one
          * of these transports will satisfy the request.  If no particular transports
diff --git a/core/java/android/net/ProxyInfo.java b/core/java/android/net/ProxyInfo.java
index 2c90909..5f5e623 100644
--- a/core/java/android/net/ProxyInfo.java
+++ b/core/java/android/net/ProxyInfo.java
@@ -35,13 +35,7 @@
  *
  * Other HTTP stacks will need to obtain the proxy info from
  * {@link Proxy#PROXY_CHANGE_ACTION} broadcast as the extra {@link Proxy#EXTRA_PROXY_INFO}.
- *
- * @deprecated Please use {@link java.net.URL#openConnection}, {@link java.net.Proxy} and
- *     friends. The Apache HTTP client is no longer maintained and may be removed in a future
- *     release. Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
- *     for further details.
  */
-@Deprecated
 public class ProxyInfo implements Parcelable {
 
     private String mHost;
diff --git a/core/tests/coretests/src/android/net/LinkPropertiesTest.java b/core/tests/coretests/src/android/net/LinkPropertiesTest.java
index abfed6e..5c55efb 100644
--- a/core/tests/coretests/src/android/net/LinkPropertiesTest.java
+++ b/core/tests/coretests/src/android/net/LinkPropertiesTest.java
@@ -17,6 +17,7 @@
 package android.net;
 
 import android.net.LinkProperties;
+import android.net.LinkProperties.ProvisioningChange;
 import android.net.RouteInfo;
 import android.system.OsConstants;
 import android.test.suitebuilder.annotation.SmallTest;
@@ -34,7 +35,8 @@
     private static InetAddress DNS6 = NetworkUtils.numericToInetAddress("2001:4860:4860::8888");
     private static InetAddress GATEWAY1 = NetworkUtils.numericToInetAddress("75.208.8.1");
     private static InetAddress GATEWAY2 = NetworkUtils.numericToInetAddress("69.78.8.1");
-    private static InetAddress GATEWAY6 = NetworkUtils.numericToInetAddress("fe80::6:0000:613");
+    private static InetAddress GATEWAY61 = NetworkUtils.numericToInetAddress("fe80::6:0000:613");
+    private static InetAddress GATEWAY62 = NetworkUtils.numericToInetAddress("fe80::6:2222");
     private static String NAME = "qmi0";
     private static int MTU = 1500;
 
@@ -466,6 +468,8 @@
         assertFalse("v4only:addr+dns", lp4.isProvisioned());
         lp4.addRoute(new RouteInfo(GATEWAY1));
         assertTrue("v4only:addr+dns+route", lp4.isProvisioned());
+        assertTrue("v4only:addr+dns+route", lp4.isIPv4Provisioned());
+        assertFalse("v4only:addr+dns+route", lp4.isIPv6Provisioned());
 
         LinkProperties lp6 = new LinkProperties();
         assertFalse("v6only:empty", lp6.isProvisioned());
@@ -473,11 +477,14 @@
         assertFalse("v6only:fe80-only", lp6.isProvisioned());
         lp6.addDnsServer(DNS6);
         assertFalse("v6only:fe80+dns", lp6.isProvisioned());
-        lp6.addRoute(new RouteInfo(GATEWAY6));
+        lp6.addRoute(new RouteInfo(GATEWAY61));
         assertFalse("v6only:fe80+dns+route", lp6.isProvisioned());
         lp6.addLinkAddress(LINKADDRV6);
+        assertTrue("v6only:fe80+global+dns+route", lp6.isIPv6Provisioned());
         assertTrue("v6only:fe80+global+dns+route", lp6.isProvisioned());
         lp6.removeLinkAddress(LINKADDRV6LINKLOCAL);
+        assertFalse("v6only:global+dns+route", lp6.isIPv4Provisioned());
+        assertTrue("v6only:global+dns+route", lp6.isIPv6Provisioned());
         assertTrue("v6only:global+dns+route", lp6.isProvisioned());
 
         LinkProperties lp46 = new LinkProperties();
@@ -487,15 +494,77 @@
         lp46.addDnsServer(DNS6);
         assertFalse("dualstack:missing-routes", lp46.isProvisioned());
         lp46.addRoute(new RouteInfo(GATEWAY1));
+        assertTrue("dualstack:v4-provisioned", lp46.isIPv4Provisioned());
+        assertFalse("dualstack:v4-provisioned", lp46.isIPv6Provisioned());
         assertTrue("dualstack:v4-provisioned", lp46.isProvisioned());
-        lp6.addRoute(new RouteInfo(GATEWAY6));
+        lp46.addRoute(new RouteInfo(GATEWAY61));
+        assertTrue("dualstack:both-provisioned", lp46.isIPv4Provisioned());
+        assertTrue("dualstack:both-provisioned", lp46.isIPv6Provisioned());
         assertTrue("dualstack:both-provisioned", lp46.isProvisioned());
 
         // A link with an IPv6 address and default route, but IPv4 DNS server.
         LinkProperties mixed = new LinkProperties();
         mixed.addLinkAddress(LINKADDRV6);
         mixed.addDnsServer(DNS1);
-        mixed.addRoute(new RouteInfo(GATEWAY6));
+        mixed.addRoute(new RouteInfo(GATEWAY61));
+        assertFalse("mixed:addr6+route6+dns4", mixed.isIPv4Provisioned());
+        assertFalse("mixed:addr6+route6+dns4", mixed.isIPv6Provisioned());
         assertFalse("mixed:addr6+route6+dns4", mixed.isProvisioned());
     }
+
+    @SmallTest
+    public void testCompareProvisioning() {
+        LinkProperties v4lp = new LinkProperties();
+        v4lp.addLinkAddress(LINKADDRV4);
+        v4lp.addRoute(new RouteInfo(GATEWAY1));
+        v4lp.addDnsServer(DNS1);
+        assertTrue(v4lp.isProvisioned());
+
+        LinkProperties v4r = new LinkProperties(v4lp);
+        v4r.removeDnsServer(DNS1);
+        assertFalse(v4r.isProvisioned());
+
+        assertEquals(ProvisioningChange.STILL_NOT_PROVISIONED,
+                LinkProperties.compareProvisioning(v4r, v4r));
+        assertEquals(ProvisioningChange.LOST_PROVISIONING,
+                LinkProperties.compareProvisioning(v4lp, v4r));
+        assertEquals(ProvisioningChange.GAINED_PROVISIONING,
+                LinkProperties.compareProvisioning(v4r, v4lp));
+        assertEquals(ProvisioningChange.STILL_PROVISIONED,
+                LinkProperties.compareProvisioning(v4lp, v4lp));
+
+        // Check that losing IPv4 provisioning on a dualstack network is
+        // seen as a total loss of provisioning.
+        LinkProperties v6lp = new LinkProperties();
+        v6lp.addLinkAddress(LINKADDRV6);
+        v6lp.addRoute(new RouteInfo(GATEWAY61));
+        v6lp.addDnsServer(DNS6);
+        assertFalse(v6lp.isIPv4Provisioned());
+        assertTrue(v6lp.isIPv6Provisioned());
+        assertTrue(v6lp.isProvisioned());
+
+        LinkProperties v46lp = new LinkProperties(v6lp);
+        v46lp.addLinkAddress(LINKADDRV4);
+        v46lp.addRoute(new RouteInfo(GATEWAY1));
+        v46lp.addDnsServer(DNS1);
+        assertTrue(v46lp.isIPv4Provisioned());
+        assertTrue(v46lp.isIPv6Provisioned());
+        assertTrue(v46lp.isProvisioned());
+
+        assertEquals(ProvisioningChange.STILL_PROVISIONED,
+                LinkProperties.compareProvisioning(v6lp, v46lp));
+        assertEquals(ProvisioningChange.LOST_PROVISIONING,
+                LinkProperties.compareProvisioning(v46lp, v6lp));
+
+        // Check that losing and gaining a secondary router does not change
+        // the provisioning status.
+        LinkProperties v6lp2 = new LinkProperties(v6lp);
+        v6lp2.addRoute(new RouteInfo(GATEWAY62));
+        assertTrue(v6lp2.isProvisioned());
+
+        assertEquals(ProvisioningChange.STILL_PROVISIONED,
+                LinkProperties.compareProvisioning(v6lp2, v6lp));
+        assertEquals(ProvisioningChange.STILL_PROVISIONED,
+                LinkProperties.compareProvisioning(v6lp, v6lp2));
+    }
 }