[Media Router] Add integration browser tests

chrome/test/media_router/media_router_base_browsertest.cc

 // Copyright 2015 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 "chrome/test/media_router/media_router_base_browsertest.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/path_service.h"
@@ skipping 49 matching lines @@
 
 void MediaRouterBaseBrowserTest::TearDownOnMainThread() {
   UninstallMRExtension();
   extensions::ProcessManager* process_manager =
       extensions::ProcessManager::Get(browser()->profile());
   DCHECK(process_manager);
   process_manager->RemoveObserver(this);
   ExtensionBrowserTest::TearDownOnMainThread();
 }
 
+Browser* MediaRouterBaseBrowserTest::GetIncognitoBrowserWithMRExtension() {
+  extension_load_event_.Reset();
+  LoadExtensionIncognito(extension_unpacked_);

[mark a. foltz, 2017/01/20 19:00:09]

What if is_unpacked() == false?

+  extension_load_event_.Wait();
+
+  return CreateIncognitoBrowser();
+}
+
 void MediaRouterBaseBrowserTest::InstallAndEnableMRExtension() {
   if (is_unpacked()) {
     const extensions::Extension* extension = LoadExtension(extension_unpacked_);
     extension_id_ = extension->id();
   } else {
     NOTIMPLEMENTED();

[mark a. foltz, 2017/01/20 19:00:09]

Can we just assume is_unpacked() is always true?

(I'm not familiar with this class specifically or why it needs to handle packed
and unpacked extensions.)

[takumif, 2017/02/07 22:17:35]

Lei said there were plans to support packaged extension but it's not happening,
so it's okay to remove it.

   }
 }
 
 void MediaRouterBaseBrowserTest::UninstallMRExtension() {
   if (!extension_id_.empty()) {
     UninstallExtension(extension_id_);
   }
 }
 
 bool MediaRouterBaseBrowserTest::ConditionalWait(
@@ skipping 44 matching lines @@
     if (PathExists(extension_path)) {
       extension_unpacked_ = extension_path;
     }
   }
 
   // Exactly one of these two arguments should be provided.
   ASSERT_NE(extension_crx_.empty(), extension_unpacked_.empty());
 }
 
 }  // namespace media_router