Re-land alexbost's experimental offscreenTabs API.

chrome/test/data/extensions/api_test/offscreen_tabs/keyboard_events.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 testTab = { url: 'a.html', width: 200, height: 200 };
+var testTabId;
+
+chrome.test.runTests([
+  function init() {
+    chrome.test.listenOnce(
+        chrome.experimental.offscreenTabs.onUpdated,
+        function(tabId, changeInfo, tab) {
+      assertSimilarTabs(testTab, tab);
+    });
+
+    chrome.experimental.offscreenTabs.create(testTab, pass(function(tab) {
+      assertSimilarTabs(testTab, tab);
+      testTabId = tab.id;
+    }));
+  },
+
+  // Test that keyboard events work by sending a 'q' keypress to a.html. The
+  // page has a keypress handler that will navigate the page to c.html.
+  function keyPress() {
+    chrome.test.listenOnce(
+        chrome.experimental.offscreenTabs.onUpdated,
+        function(tabId, changeInfo, tab) {
+      testTab.url = 'c.html';
+      assertEq(maybeExpandURL('c.html'), changeInfo.url);
+      assertSimilarTabs(testTab, tab);
+      assertEq(tabId, tab.id);
+      assertEq(tabId, testTabId);
+    });
+
+    chrome.experimental.offscreenTabs.sendKeyboardEvent(
+        testTabId, getKeyboardEvent(Q_KEY), pass(function() {
+      chrome.experimental.offscreenTabs.get(testTabId, pass(function(tab) {
+        assertSimilarTabs(testTab, tab);
+      }));
+    }));
+  }
+
+  // TODO(jstritar): Test event validation and edge cases.
+]);