Add API stubs for GCD device commands.

chrome/test/data/extensions/api_test/gcd_private/api/remove_device.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 onload = function() {
   chrome.test.runTests([
-    function addRemoveDevice() {
-      var should_be_available = true;
-      chrome.gcdPrivate.onCloudDeviceStateChanged.addListener(
-        function(available, device) {
-          chrome.test.assertEq(available, should_be_available);
-          should_be_available = false;
-
-          chrome.test.assertEq(device.setupType, "mdns");
-          chrome.test.assertEq(device.idString,
-                               "mdns:myService._privet._tcp.local");
-          chrome.test.assertEq(device.deviceType, "printer");
-          chrome.test.assertEq(device.deviceName,
-                               "Sample device");
-          chrome.test.assertEq(device.deviceDescription,
-                               "Sample device description");
-
-          if (!available) {
-            // Only pass after device is removed
-            chrome.test.notifyPass();
-          }
-    })
+      function addRemoveDevice() {
+        chrome.gcdPrivate.onDeviceRemoved.addListener(
+            function(deviceId) {
+              chrome.test.assertEq(deviceId,
+                                   "mdns:myService._privet._tcp.local");
+              chrome.test.notifyPass();
+            })
   }]);
 };