[Cast MRP] Removed warning for client_connect messages.

Bug: b/169327785
Change-Id: I70339ef33a19af6e2a9be3081429e0856ef145a0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2487560Reviewed-by: Takumi Fujimoto <takumif@chromium.org>
Commit-Queue: John Williams <jrw@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825541}

chrome/browser/media/router/providers/cast/cast_session_client_impl.cc

@@ -199,6 +199,11 @@ void CastSessionClientImpl::HandleParsedClientMessage(
       activity_->HandleLeaveSession(client_id());
       break;
 
+    case CastInternalMessage::Type::kClientConnect:
+      // This message type is obsolete and can be safely ignored (see b/34104690
+      // and the corresponding TODO in the Cast API implementation).
+      break;
+
     default:
       auto opt_string = cast_util::EnumToString(cast_message->type());
       if (opt_string) {