Workaround NetworkConnectionManager race condition

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
index da4b9163a6744c972e380ef9affb974ccee23ff8..2b0c6c0eac50a29133d96c69f59bc71e49ffac56 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageUtils.java
@@ -8,6 +8,8 @@ import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
 import android.net.Uri;
 import android.os.AsyncTask;
 import android.os.BatteryManager;
@@ -636,9 +638,41 @@ public class OfflinePageUtils {
         Intent batteryStatus = context.registerReceiver(null, filter);
         if (batteryStatus == null) return null;
 
-        return new DeviceConditions(isPowerConnected(batteryStatus),
-                batteryPercentage(batteryStatus),
-                NetworkChangeNotifier.getInstance().getCurrentConnectionType());
+        // Get the connection type from chromium's internal object.
+        int connectionType = NetworkChangeNotifier.getInstance().getCurrentConnectionType();
+
+        // Sometimes the NetworkConnectionNotifier lags the actual connection type, especially when
+        // the GCM NM wakes us from doze state.  If we are really connected, report the connection
+        // type from android.
+        if (connectionType == ConnectionType.CONNECTION_NONE) {
+            // Get the connection type from android in case chromium's type is not yet set.
+            ConnectivityManager cm =
+                    (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
+            NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
+            boolean isConnected = activeNetwork != null && activeNetwork.isConnectedOrConnecting();
+            if (isConnected) {
+                connectionType = convertAndroidNetworkTypeToConnectionType(activeNetwork.getType());

[dougarnett, 2017/01/13 23:13:16]

With the convert method now why bother with NetworkChangeNotifier?
Just use Android ConnectivityManager and convert it?

[Pete Williamson, 2017/01/13 23:15:39]

My thinking is that if NCN is available, it has better granularity.  It knows
the difference between 2G, 3G, and 4G, while android ConnectivityManager does
not.  So, if we get something from NCN, it is likely better.  

[dougarnett, 2017/01/14 00:59:11]

Ah, yuck, looked a bit into the multi-version mess of getting to those
classifications! 

Might be nice if we could kick NCN or I suppose the
NetworkChangeNotifierAutoDetect with new current network type (instead of it
waiting for its turn to receive the broadcast with the changed network type).

[Pete Williamson, 2017/01/14 01:08:10]

One thing I got from the bug I filed on NCN is that we could use our own NCN
instance instead of the regular chrome one, and we can ask it to stay awake
while chrome is in the background.  However, this fix seems simpler for M56. 
Also, we may be causing lots of unnecessary CPU usage since chrome would watch
for all net changes in the background just in case there is a background page
request, so that would take a bit of study before we know if it is the right
course of action.

Furthermore, today we don't really do much with the connection type.  Someday we
may change our timeout based on connection type.

+            }
+        }
+
+        return new DeviceConditions(
+                isPowerConnected(batteryStatus), batteryPercentage(batteryStatus), connectionType);
+    }
+
+    /** Returns the NCN network type corresponding to the connectivity manager network type */
+    protected int convertAndroidNetworkTypeToConnectionType(int connectivityManagerNetworkType) {
+        if (connectivityManagerNetworkType == ConnectivityManager.TYPE_WIFI) {
+            return ConnectionType.CONNECTION_WIFI;
+        }
+        // for mobile, we don't know if it is 2G, 3G, or 4G, default to worst case of 2G.

[dougarnett, 2017/01/14 00:59:11]

Possible TODO idea - look at exposing mapping utility method from NCN or NCNAD.

[Pete Williamson, 2017/01/14 01:08:10]

Noted, but I'd prefer to wait until I checkout the new NCN instance for M57
before adding that TODO.  If you want to be sure the idea doesn't get lost,
though, I'd be happy to add it.

+        if (connectivityManagerNetworkType == ConnectivityManager.TYPE_MOBILE) {
+            return ConnectionType.CONNECTION_2G;
+        }
+        if (connectivityManagerNetworkType == ConnectivityManager.TYPE_BLUETOOTH) {
+            return ConnectionType.CONNECTION_BLUETOOTH;
+        }
+        // Since NetworkConnectivityManager doesn't understand the other types, call them UNKNOWN.
+        return ConnectionType.CONNECTION_UNKNOWN;
     }
 
     @VisibleForTesting