Adding ability to set alert credentials via remote

This change is twofold. First, it adds a method to the Alert interface in
the Java language bindings to enable the ability to set credentials
without implicitly clicking OK on the authentication alert. The first
change enables the second, which is to expose the 'set alert credentials'
wire protocol end point to users of the Java remote server.

Author: jimevans

Diff for: java/client/src/org/openqa/selenium/Alert.java

@@ -28,6 +28,9 @@ public interface Alert {
 
   void sendKeys(String keysToSend);
 
+  @Beta
+  void setCredentials(Credentials credentials);
+
   /**
    * Authenticate an HTTP Basic Auth dialog.
    *

Diff for: java/client/src/org/openqa/selenium/remote/RemoteWebDriver.java

@@ -934,6 +934,13 @@ public void sendKeys(String keysToSend) {
       execute(DriverCommand.SET_ALERT_VALUE, ImmutableMap.of("text", keysToSend));
     }
 
+    @Beta
+    public void setCredentials(Credentials credentials) {
+      execute(DriverCommand.SET_ALERT_CREDENTIALS, ImmutableMap
+        .of("username", credentials.getUserPrincipal().getName(), "password",
+            credentials.getPassword()));
+    }
+
     /**
      * Authenticate an HTTP Basic Auth dialog.
      * Implicitly 'clicks ok'
@@ -944,9 +951,7 @@ public void sendKeys(String keysToSend) {
      */
     @Beta
     public void authenticateUsing(Credentials credentials) {
-      execute(DriverCommand.SET_ALERT_CREDENTIALS, ImmutableMap
-        .of("username", credentials.getUserPrincipal().getName(), "password",
-            credentials.getPassword()));
+      this.setCredentials(credentials);
       this.accept();
     }
   }

Diff for: java/server/src/org/openqa/selenium/remote/server/JsonHttpCommandHandler.java

@@ -88,6 +88,7 @@
 import org.openqa.selenium.remote.server.handler.Rotate;
 import org.openqa.selenium.remote.server.handler.SendKeys;
 import org.openqa.selenium.remote.server.handler.SetAlertText;
+import org.openqa.selenium.remote.server.handler.SetAlertCredentials;
 import org.openqa.selenium.remote.server.handler.SetScriptTimeout;
 import org.openqa.selenium.remote.server.handler.SetWindowPosition;
 import org.openqa.selenium.remote.server.handler.SetWindowSize;
@@ -204,6 +205,7 @@ private void setUpMappings() {
     addNewMapping(ACCEPT_ALERT, AcceptAlert.class);
     addNewMapping(GET_ALERT_TEXT, GetAlertText.class);
     addNewMapping(SET_ALERT_VALUE, SetAlertText.class);
+    addNewMapping(SET_ALERT_CREDENTIALS, SetAlertCredentials.class);
 
     addNewMapping(GET, ChangeUrl.class);
     addNewMapping(GET_CURRENT_URL, GetCurrentUrl.class);

Diff for: java/server/src/org/openqa/selenium/remote/server/handler/SetAlertCredentials.java

@@ -0,0 +1,52 @@
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package org.openqa.selenium.remote.server.handler;
+
+import org.apache.http.auth.Credentials;
+import org.apache.http.auth.UsernamePasswordCredentials;
+
+import org.openqa.selenium.remote.server.JsonParametersAware;
+import org.openqa.selenium.remote.server.Session;
+
+import java.util.Map;
+
+public class SetAlertCredentials extends WebDriverHandler<Void> implements JsonParametersAware {
+  private String username;
+  private String password;
+
+  public SetAlertCredentials(Session session) {
+    super(session);
+  }
+
+  public void setJsonParameters(Map<String, Object> allParameters) throws Exception {
+    username = (String) allParameters.get("username");
+    password = (String) allParameters.get("password");
+  }
+
+  @Override
+  public Void call() throws Exception {
+    UsernamePasswordCredentials credentials = new UsernamePasswordCredentials(username, password);
+    getDriver().switchTo().alert().setCredentials(credentials);
+    return null;
+  }
+
+  @Override
+  public String toString() {
+    return "[set alert credentials]";
+  }
+}