Add a new app API to enable watchdog behavior restarts in kiosk apps

chrome/test/data/extensions/api_test/runtime/restartOnWatchdog/test.js

+// Copyright 2016 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.
+
+var assertEq = chrome.test.assertEq;
+var assertTrue = chrome.test.assertTrue;
+var assertFalse = chrome.test.assertFalse;
+var fail = chrome.test.fail;
+var succeed = chrome.test.succeed;
+
+chrome.test.runTests([
+
+  function testRestartOnWatchdog() {
+    chrome.runtime.restartOnWatchdog(1, function() {
+      // This will be canceled by the following call, and we should never
+      // receive a callback.
+      fail();
+    });
+
+    chrome.runtime.restartOnWatchdog(1, function() {
+      // This will be canceled by the following call, and we should never
+      // receive a callback.
+      fail();
+    });
+
+    var start = Date.now();
+    chrome.runtime.restartOnWatchdog(2, function(success, message) {
+      assertTrue(success);
+
+      var end = Date.now();
+      if ((end - start) < 2000) {
+        console.log('Error: Restarting sooner than requested: ' +
+            (end - start) + ' ms.');
+        fail();
+      }
+
+      succeed();
+    });
+  },
+
+  function testThrottlingRestartRequests() {
+    chrome.runtime.restartOnWatchdog(3, function(success, message) {
+      // This request will succeed.
+      assertTrue(success);
+
+      chrome.runtime.restartOnWatchdog(1, function(success, message) {
+        // This request will be throttled.
+        assertEq(message, 'Error: Called too soon since the last restart.');
+        assertFalse(success);
+        succeed();
+      });
+    });
+  }
+
+]);