Expose quota status for active network.

Create API to expose quota status derived from underlying network
policy.  This is designed to support applications making informed
decisions when performing network requests.

Fix bug with random stats generation, and write policy when changing
restrict background data flag.  Deprecate EXTRA_NETWORK_INFO, since
it varies based on UID.

Bug: 4517283, 5088603
Change-Id: Ic6893a8967f69937e466be226ba7bb86ef5a5d2d
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index a564d97..eb9cd21 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -16,10 +16,11 @@
 
 package android.net;
 
+import static com.android.internal.util.Preconditions.checkNotNull;
+
 import android.annotation.SdkConstant;
 import android.annotation.SdkConstant.SdkConstantType;
 import android.os.Binder;
-import android.os.ParcelFileDescriptor;
 import android.os.RemoteException;
 
 import java.net.InetAddress;
@@ -67,11 +68,19 @@
      * is set to {@code true} if there are no connected networks at all.
      */
     public static final String CONNECTIVITY_ACTION = "android.net.conn.CONNECTIVITY_CHANGE";
+
     /**
      * The lookup key for a {@link NetworkInfo} object. Retrieve with
      * {@link android.content.Intent#getParcelableExtra(String)}.
+     *
+     * @deprecated Since {@link NetworkInfo} can vary based on UID, applications
+     *             should always obtain network information through
+     *             {@link #getActiveNetworkInfo()} or
+     *             {@link #getAllNetworkInfo()}.
      */
+    @Deprecated
     public static final String EXTRA_NETWORK_INFO = "networkInfo";
+
     /**
      * The lookup key for a boolean that indicates whether a connect event
      * is for a network to which the connectivity manager was failing over
@@ -515,6 +524,19 @@
     }
 
     /**
+     * Return quota status for the current active network, or {@code null} if no
+     * network is active. Quota status can change rapidly, so these values
+     * shouldn't be cached.
+     */
+    public NetworkQuotaInfo getActiveNetworkQuotaInfo() {
+        try {
+            return mService.getActiveNetworkQuotaInfo();
+        } catch (RemoteException e) {
+            return null;
+        }
+    }
+
+    /**
      * Gets the value of the setting for enabling Mobile data.
      *
      * @return Whether mobile data is enabled.
@@ -546,10 +568,7 @@
      * {@hide}
      */
     public ConnectivityManager(IConnectivityManager service) {
-        if (service == null) {
-            throw new IllegalArgumentException("missing IConnectivityManager");
-        }
-        mService = service;
+        mService = checkNotNull(service, "missing IConnectivityManager");
     }
 
     /**