Adds helper methods for WebView.

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

Index: net/android/java/src/org/chromium/net/ProxyChangeListener.java
diff --git a/net/android/java/src/org/chromium/net/ProxyChangeListener.java b/net/android/java/src/org/chromium/net/ProxyChangeListener.java
index 5bd3a812d7c385c918d524d6b907a54f872ad100..37869dbbb2d04cf56f1f68fe1248b10f43e1a8a5 100644
--- a/net/android/java/src/org/chromium/net/ProxyChangeListener.java
+++ b/net/android/java/src/org/chromium/net/ProxyChangeListener.java
@@ -19,15 +19,29 @@ import org.chromium.base.NativeClassQualifiedName;
 @JNINamespace("net")
 public class ProxyChangeListener {
     private static final String TAG = "ProxyChangeListener";
+    private static boolean sEnabled = true;
 
     private int mNativePtr;
     private Context mContext;
     private ProxyReceiver mProxyReceiver;
+    private Delegate mDelegate;
+
+    public interface Delegate {
+      public void proxySettingsChanged();
+    }
 
     private ProxyChangeListener(Context context) {
         mContext = context;
     }
 
+    public static void setEnabled(boolean enabled) {
+        sEnabled = enabled;
+    }
+
+    public void setDelegateForTesting(Delegate delegate) {
+        mDelegate = delegate;
+    }
+
     @CalledByNative
     static public ProxyChangeListener create(Context context) {
         return new ProxyChangeListener(context);