[chrome.displaySource] Add WiFi Display session class skeleton and mojo service

extensions/renderer/display_source_custom_bindings.cc

Index: extensions/renderer/display_source_custom_bindings.cc
diff --git a/extensions/renderer/display_source_custom_bindings.cc b/extensions/renderer/display_source_custom_bindings.cc
index 059d2bbff6d17ba416904a310fe657144c62fad8..a31620778cf9aadd44b72ed7e2d19342ca472a81 100644
--- a/extensions/renderer/display_source_custom_bindings.cc
+++ b/extensions/renderer/display_source_custom_bindings.cc
@@ -133,9 +133,17 @@ void DisplaySourceCustomBindings::StartSession(
     auth_info = DisplaySourceAuthInfo::FromValue(*auth_info_val);
   }
 
+  DisplaySourceSessionParams session_params;
+  session_params.sink_id = sink_id;
+  session_params.video_track = video_track;
+  session_params.audio_track = audio_track;
+  session_params.render_frame = context()->GetRenderFrame();
+  if (auth_info) {
+    session_params.auth_method = auth_info->method;
+    session_params.auth_data = auth_info->data ? *auth_info->data : "";
+  }
   scoped_ptr<DisplaySourceSession> session =
-      DisplaySourceSessionFactory::CreateSession(
-          sink_id, video_track, audio_track, std::move(auth_info));
+      DisplaySourceSessionFactory::CreateSession(session_params);
   if (!session) {
     isolate->ThrowException(v8::Exception::Error(v8::String::NewFromUtf8(
         isolate, kErrorNotSupported)));
@@ -154,8 +162,8 @@ void DisplaySourceCustomBindings::StartSession(
   session->SetCallbacks(on_started_callback,
                         on_terminated_callback,
                         on_error_callback);
-  session_map_.insert(std::make_pair(sink_id, std::move(session)));
   session->Start();
+  session_map_.insert(std::make_pair(sink_id, std::move(session)));
 }
 
 void DisplaySourceCustomBindings::TerminateSession(