Tabs Extension: Implementation of tabs.duplicate api.

chrome/test/data/extensions/api_test/tabs/basics/duplicate.js

+// Copyright (c) 2011 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 firstTabId;
+var firstWindowId;
+
+chrome.test.runTests([
+  function setupWindow() {
+    createWindow([pageUrl("a")], {},
+                 pass(function(winId, tabIds) {
+      firstWindowId = winId;
+      firstTabId = tabIds[0];
+    }));
+  },
+
+  function duplicateTab() {
+    chrome.tabs.duplicate(firstTabId, pass(function(tab) {
+      assertEq(pageUrl("a"), tab.url);
+      assertEq(1, tab.index);
+    }));
+  },
+
+  function totalTab() {
+    chrome.tabs.getAllInWindow(firstWindowId,
+      pass(function(tabs) {
+        assertEq(tabs.length, 2);
+        assertEq(tabs[0].url, tabs[1].url);
+        assertEq(tabs[0].index + 1, tabs[1].index);
+      }));
+  }
+]);