[Media Router] Implement JoinRoute + update CreateRoute API.

chrome/chrome_tests_unit.gypi

 # Copyright 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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       '../components/autofill/content/renderer/test_password_autofill_agent.cc',
       '../components/autofill/content/renderer/test_password_autofill_agent.h',
       '../components/autofill/content/renderer/test_password_generation_agent.cc',
       '../components/autofill/content/renderer/test_password_generation_agent.h',
@@ skipping 1416 matching lines @@
       'browser/supervised_user/legacy/supervised_user_shared_settings_update_unittest.cc',
       'browser/supervised_user/legacy/supervised_user_sync_service_unittest.cc',
       'browser/supervised_user/supervised_user_bookmarks_handler_unittest.cc',
       'browser/supervised_user/supervised_user_pref_store_unittest.cc',
       'browser/supervised_user/supervised_user_service_unittest.cc',
       'browser/supervised_user/supervised_user_settings_service_unittest.cc',
       'browser/supervised_user/supervised_user_url_filter_unittest.cc',
       'browser/supervised_user/supervised_user_whitelist_service_unittest.cc',
     ],
     'chrome_unit_tests_media_router_sources': [
+      'browser/media/router/create_session_request_unittest.cc',
       'browser/media/router/issue_manager_unittest.cc',
       'browser/media/router/issue_unittest.cc',
       'browser/media/router/media_router_mojo_impl_unittest.cc',
       'browser/media/router/media_router_type_converters_unittest.cc',
       'browser/media/router/media_route_unittest.cc',
       'browser/media/router/media_sink_unittest.cc',
       'browser/media/router/media_source_helper_unittest.cc',
       'browser/media/router/media_source_unittest.cc',
       'browser/media/router/presentation_media_sinks_observer_unittest.cc',
       'browser/media/router/presentation_service_delegate_impl_unittest.cc',
@@ skipping 1399 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }