Re-land alexbost's experimental offscreenTabs API.

chrome/test/data/extensions/api_test/offscreen_tabs/crud.js

+// Copyright (c) 2012 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 tabList = [
+  { url: 'a.html', width: 200, height: 200 },
+  { url: 'b.html', width: 200, height: 200 },
+  { url: 'c.html', width: 1000,height: 800 }
+];
+
+// Holds the tab objects once they're created.
+var tabs = [];
+
+chrome.test.runTests([
+  function create() {
+    tabList.forEach(function(tab) {
+      chrome.experimental.offscreenTabs.create(
+          tab, pass(function(offscreenTab) {
+        tabs.push(offscreenTab);
+        assertSimilarTabs(tab, offscreenTab);
+      }));
+    });
+  },
+
+  function getAll() {
+    chrome.experimental.offscreenTabs.getAll(pass(function(offscreenTabs) {
+      var tabSorter = function(tab1, tab2) { return tab1.id - tab2.id; };
+      offscreenTabs.sort(tabSorter);
+      tabs.sort(tabSorter);
+      assertEq(tabs.length, offscreenTabs.length);
+      assertEq(tabs.length, tabList.length);
+      for (var i = 0; i < tabs.length; i++)
+        assertEqTabs(tabs[i], offscreenTabs[i]);
+    }));
+  },
+
+  function get() {
+    chrome.experimental.offscreenTabs.get(tabs[0].id, pass(function(tab) {
+      assertEqTabs(tabs[0], tab);
+    }));
+  },
+
+  function update() {
+    chrome.test.listenOnce(
+        chrome.experimental.offscreenTabs.onUpdated,
+        function(tabId, changeInfo, tab) {
+      assertSimilarTabs(tabList[0], tab);
+    });
+
+    // Update the 2nd tab to be like the 1st one.
+    chrome.experimental.offscreenTabs.update(
+        tabs[1].id, tabList[0], pass(function() {
+      chrome.experimental.offscreenTabs.get(tabs[1].id, pass(function(tab) {
+        assertSimilarTabs(tabList[0], tab);
+      }));
+    }));
+  },
+
+  function remove() {
+    tabs.forEach(function(tab) {
+      chrome.experimental.offscreenTabs.remove(tab.id, pass(function() {
+        assertTabDoesNotExist(tab.id);
+      }));
+    });
+  }
+]);