Support shared workers as debug targets for chrome.debugger API

chrome/test/data/extensions/api_test/debugger_extension/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.
 
 var pass = chrome.test.callbackPass;
 var fail = chrome.test.callbackFail;
 
 var debuggee;
 var protocolVersion = "1.0";
 
@@ skipping 19 matching lines @@
   },
 
   function detach() {
     chrome.debugger.detach(debuggee, pass());
   },
 
   function detachAgain() {
     chrome.debugger.detach(debuggee,
         fail("Debugger is not attached to the background page with id: " +
             debuggee.extensionId + "."));
+  },
+
+  function discoverWorker() {
+    chrome.test.listenOnce(chrome.tabs.onUpdated, function () {
+      chrome.debugger.getTargets(function(targets) {
+        var page = targets.filter(
+                function(t) { return t.type == 'worker'; })[0];
+        if (page) {
+          chrome.debugger.attach({targetId: page.id}, protocolVersion, pass());
+        } else {
+          chrome.test.fail("Cannot discover a newly created worker");
+        }
+      });
+    });
+    chrome.tabs.create({url: "worker.html"});
   }
 ]);