Extract debugger target enumeration into a separate class

chrome/test/data/devtools/target_list/background.js

+// Copyright (c) 2013 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.
+
+function requestUrl(url, callback) {
+  var req = new XMLHttpRequest();
+  req.open('GET', url, true);
+  req.onload = function() {
+    if (req.status == 200)
+      callback(req.responseText);
+    else
+      req.onerror();
+  };
+  req.onerror = function() {
+    chrome.test.fail('XHR failed: ' + req.status);
+  };
+  req.send(null);
+}
+
+var REMOTE_DEBUGGER_HOST = 'localhost:9222';
+
+function checkTarget(targets, url, type, opt_title, opt_faviconUrl) {
+  var target =
+      targets.filter(function(t) { return t.url == url }) [0];
+  if (!target)
+    chrome.test.fail('Cannot find a target with url ' + url);
+
+  var wsAddress = REMOTE_DEBUGGER_HOST + '/devtools/page/' + target.id;
+
+  chrome.test.assertEq(
+      '/devtools/devtools.html?ws=' + wsAddress,
+      target.devtoolsFrontendUrl);
+  chrome.test.assertEq(opt_faviconUrl || '', target.faviconUrl);
+  chrome.test.assertEq('/thumb/' + target.id, target.thumbnailUrl);
+  chrome.test.assertEq(opt_title || target.url, target.title);
+  chrome.test.assertEq(type, target.type);
+  chrome.test.assertEq('ws://' + wsAddress, target.webSocketDebuggerUrl);
+}
+
+chrome.test.runTests([
+  function discoverTargets() {
+    var testPageUrl = chrome.extension.getURL('test_page.html');
+
+    function onUpdated() {
+      chrome.tabs.onUpdated.removeListener(onUpdated);
+      requestUrl('http://' + REMOTE_DEBUGGER_HOST + '/json', function(text) {
+        var targets = JSON.parse(text);
+
+        checkTarget(targets, 'about:blank', 'page');
+        checkTarget(targets, testPageUrl, 'page', 'Test page',
+            chrome.extension.getURL('favicon.png'));
+        checkTarget(targets,
+            chrome.extension.getURL('_generated_background_page.html'),
+            'other');
+
+        chrome.test.succeed();
+      });
+    }
+    chrome.tabs.onUpdated.addListener(onUpdated);
+    chrome.tabs.create({url: testPageUrl});
+  }
+]);