NCN: Get the current network's info

Get the current network's info in NetworkChangeNotifier by calling
getActiveNetworkInfo and unblocking the network if possible.

BUG=677365
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_cronet_tester

Review-Url: https://codereview.chromium.org/2601893003
Cr-Commit-Position: refs/heads/master@{#442676}

net/android/java/src/org/chromium/net/NetworkChangeNotifierAutoDetect.java

@@ -29,6 +29,8 @@ import android.os.Build;
 import android.telephony.TelephonyManager;
 import android.util.Log;
 
+import org.chromium.base.ApplicationState;
+import org.chromium.base.ApplicationStatus;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.metrics.RecordHistogram;
@@ -83,6 +85,14 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver {
 
     /** Queries the ConnectivityManager for information about the current connection. */
     static class ConnectivityManagerDelegate {
+        private static final int NETWORK_INFO_DISCONNECTED = 0;
+        private static final int NETWORK_INFO_CONNECTED = 1;
+        private static final int NETWORK_INFO_ANDROID_API_LEVEL_TOO_OLD_FOR_UNBLOCKING = 2;
+        private static final int NETWORK_INFO_NOT_BLOCKED = 3;
+        private static final int NETWORK_INFO_APP_NOT_IN_FOREGROUND = 4;
+        private static final int NETWORK_INFO_UNBLOCKED = 5;
+        private static final int NETWORK_INFO_BOUNDARY = 6;
+
         private final ConnectivityManager mConnectivityManager;
 
         ConnectivityManagerDelegate(Context context) {
@@ -96,13 +106,66 @@ public class NetworkChangeNotifierAutoDetect extends BroadcastReceiver {
             mConnectivityManager = null;
         }
 
+        /**
+         * @return the info of the network that is available to this app.
+         */
+        @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+        private NetworkInfo getActiveNetworkInfo() {
+            final NetworkInfo networkInfo = mConnectivityManager.getActiveNetworkInfo();
+            if (networkInfo == null) {
+                recordGetActiveNetworkInfoResult(NETWORK_INFO_DISCONNECTED);
+                return null;
+            }
+
+            if (networkInfo.isConnected()) {
+                recordGetActiveNetworkInfoResult(NETWORK_INFO_CONNECTED);
+                return networkInfo;
+            }
+
+            // If |networkInfo| is BLOCKED, but the app is in the foreground, then it's likely that
+            // Android hasn't finished updating the network access permissions as BLOCKED is only
+            // meant for apps in the background.  See https://crbug.com/677365 for more details.
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+                // https://crbug.com/677365 primarily affects only Lollipop and higher versions.
+                recordGetActiveNetworkInfoResult(
+                        NETWORK_INFO_ANDROID_API_LEVEL_TOO_OLD_FOR_UNBLOCKING);
+                return null;
+            }
+
+            if (networkInfo.getDetailedState() != NetworkInfo.DetailedState.BLOCKED) {
+                // Network state is not blocked which implies that network access is
+                // unavailable (not just blocked to this app).
+                recordGetActiveNetworkInfoResult(NETWORK_INFO_NOT_BLOCKED);
+                return null;
+            }
+
+            if (ApplicationStatus.getStateForApplication()
+                    != ApplicationState.HAS_RUNNING_ACTIVITIES) {
+                // The app is not in the foreground.
+                recordGetActiveNetworkInfoResult(NETWORK_INFO_APP_NOT_IN_FOREGROUND);
+                return null;
+            }
+            recordGetActiveNetworkInfoResult(NETWORK_INFO_UNBLOCKED);
+            return networkInfo;
+        }
+
+        /**
+         * Records the result of querying the network info of the current active network.
+         * @param result Result of querying the network info of the current active network.
+         */
+        private static void recordGetActiveNetworkInfoResult(int result) {
+            assert result >= 0 && result < NETWORK_INFO_BOUNDARY;
+            RecordHistogram.recordEnumeratedHistogram(
+                    "NCN.GetActiveNetworkInfoResult", result, NETWORK_INFO_BOUNDARY);
+        }
+
         /**
          * Returns connection type and status information about the current
          * default network.
          */
         NetworkState getNetworkState(WifiManagerDelegate wifiManagerDelegate) {
-            final NetworkInfo networkInfo = mConnectivityManager.getActiveNetworkInfo();
-            if (networkInfo == null || !networkInfo.isConnected()) {
+            final NetworkInfo networkInfo = getActiveNetworkInfo();
+            if (networkInfo == null) {
                 return new NetworkState(false, -1, -1, null);
             }
             // If Wifi, then fetch SSID also

tools/metrics/histograms/histograms.xml

@@ -29582,6 +29582,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Time between DNS configuration change messages.</summary>
 </histogram>
 
+<histogram name="NCN.GetActiveNetworkInfoResult"
+    enum="NCNGetActiveNetworkInfoResult">
+  <owner>pauljensen@chromium.org</owner>
+  <owner>tbansal@chromium.org</owner>
+  <summary>
+    Records the result of querying the network info of the current active
+    network. Useful for investigating how frequently the current network was
+    unblocked, and why it was not unblocked. See http://crbug.com/677365.
+  </summary>
+</histogram>
+
 <histogram name="NCN.GetConnectionTypeTime" units="ms">
   <owner>pauljensen@chromium.org</owner>
   <summary>
@@ -96863,6 +96874,15 @@ value.
   <int value="5" label="Cross-origin subframe vibrate, with user gesture"/>
 </enum>
 
+<enum name="NCNGetActiveNetworkInfoResult" type="int">
+  <int value="0" label="Active network was disconnected"/>
+  <int value="1" label="Active network was already connected"/>
+  <int value="2" label="Android API level was too old for unblocking"/>
+  <int value="3" label="Active network was not blocked"/>
+  <int value="4" label="App was not running in the background"/>
+  <int value="5" label="Active network was unblocked"/>
+</enum>
+
 <enum name="NetCacheState" type="int">
   <int value="0" label="FROM_CACHE"/>
   <int value="1" label="STILL_VALID"/>