Don't run Wifi scan timestamp tests when location is turned off.

Bug:24957400
Change-Id: I891040ffc0808d62a8f5f1bb20fd633b9f7f482c

tests/cts/net/src/android/net/wifi/cts/WifiManagerTest.java

@@ -21,6 +21,8 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.content.pm.PackageManager;
+import android.location.LocationManager;
 import android.net.NetworkInfo;
 import android.net.wifi.ScanResult;
 import android.net.wifi.WifiConfiguration;
@@ -29,6 +31,7 @@ import android.net.wifi.WifiManager;
 import android.net.wifi.WifiManager.TxPacketCountListener;
 import android.net.wifi.WifiManager.WifiLock;
 import android.os.SystemClock;
+import android.provider.Settings;
 import android.test.AndroidTestCase;
 import android.util.Log;
 
@@ -278,6 +281,14 @@ public class WifiManagerTest extends AndroidTestCase {
             Log.d(TAG, "Skipping test as WiFi is not supported");
             return;
         }
+        if (!hasLocationFeature()) {
+            Log.d(TAG, "Skipping test as location is not supported");
+            return;
+        }
+        if (!isLocationEnabled()) {
+            fail("Please enable location for this test - since Marshmallow WiFi scan results are"
+                    + " empty when location is disabled!");
+        }
         if (!mWifiManager.isWifiEnabled()) {
             setWifiEnabled(true);
         }
@@ -307,6 +318,18 @@ public class WifiManagerTest extends AndroidTestCase {
         }
     }
 
+    // Return true if location is enabled.
+    private boolean isLocationEnabled() {
+        return Settings.Secure.getInt(getContext().getContentResolver(),
+                Settings.Secure.LOCATION_MODE, Settings.Secure.LOCATION_MODE_OFF) !=
+                Settings.Secure.LOCATION_MODE_OFF;
+    }
+
+    // Returns true if the device has location feature.
+    private boolean hasLocationFeature() {
+        return getContext().getPackageManager().hasSystemFeature(PackageManager.FEATURE_LOCATION);
+    }
+
     /**
      * test point of wifiManager NetWork:
      * 1.add NetWork