Enable chrome.mdns for Chrome Apps

chrome/browser/extensions/api/mdns/mdns_apitest.cc

 // Copyright 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.
 
 #include "base/command_line.h"
 #include "chrome/browser/extensions/api/mdns/mdns_api.h"
 #include "chrome/browser/extensions/extension_apitest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/common/extensions/api/mdns.h"
 #include "extensions/common/switches.h"
@@ skipping 34 matching lines @@
   void SetUpCommandLine(base::CommandLine* command_line) override {
     ExtensionApiTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(
         extensions::switches::kWhitelistedExtensionID,
         "ddchlicdkolnonkihahngkmmmjnjlkkf");
   }
 
   void SetUpTestDnsSdRegistry() {
     extensions::MDnsAPI* api = extensions::MDnsAPI::Get(profile());
     dns_sd_registry_ = new MockDnsSdRegistry(api);
+    EXPECT_CALL(*dns_sd_registry_, AddObserver(api))
+        .Times(1);
     // Transfers ownership of the registry instance.
     api->SetDnsSdRegistryForTesting(
         make_scoped_ptr<DnsSdRegistry>(dns_sd_registry_).Pass());
   }
 
  protected:
   MockDnsSdRegistry* dns_sd_registry_;
 };
 
 }  // namespace
@@ skipping 68 matching lines @@
   DnsSdRegistry::DnsSdServiceList services;
 
   extensions::DnsSdService service;
   service.service_name = service_type;
   services.push_back(service);
 
   dns_sd_registry_->DispatchMDnsEvent(service_type, services);
   dns_sd_registry_->DispatchMDnsEvent(test_service_type, services);
   EXPECT_TRUE(catcher.GetNextResult()) << catcher.message();
 }