Ensure WorkSource for location blaming has names (b/10378815)

Change-Id: Ic201f7112dd9c746fe71995fcc1a533ff4a582f2
diff --git a/services/java/com/android/server/LocationManagerService.java b/services/java/com/android/server/LocationManagerService.java
index 9761441..95c768f 100644
--- a/services/java/com/android/server/LocationManagerService.java
+++ b/services/java/com/android/server/LocationManagerService.java
@@ -1235,8 +1235,11 @@
                     if (UserHandle.getUserId(record.mReceiver.mUid) == mCurrentUserId) {
                         LocationRequest locationRequest = record.mRequest;
                         if (locationRequest.getInterval() <= thresholdInterval) {
-                            if (record.mReceiver.mWorkSource != null) {
+                            if (record.mReceiver.mWorkSource != null
+                                    && record.mReceiver.mWorkSource.size() > 0
+                                    && record.mReceiver.mWorkSource.getName(0) != null) {
                                 // Assign blame to another work source.
+                                // Can only assign blame if the WorkSource contains names.
                                 worksource.add(record.mReceiver.mWorkSource);
                             } else {
                                 // Assign blame to caller.