Bug 971873 - ProxySelector references String.isEmpty(), which is API level 9 r=bnicholson

mobile/android/base/util/ProxySelector.java

@@ -18,6 +18,8 @@
 
 package org.mozilla.gecko.util;
 
+import android.text.TextUtils;
+
 import java.io.IOException;
 import java.net.InetSocketAddress;
 import java.net.Proxy;
@@ -79,7 +81,7 @@ public class ProxySelector {
      */
     private Proxy lookupProxy(String hostKey, String portKey, Proxy.Type type, int defaultPort) {
         String host = System.getProperty(hostKey);
-        if (host == null || host.isEmpty()) {
+        if (TextUtils.isEmpty(host)) {
             return null;
         }