[Fuchsia] Quiet an spurious error message in the EventHandler

runtime/bin/eventhandler_fuchsia.cc

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #if !defined(DART_IO_DISABLED)
 
 #include "platform/globals.h"
 #if defined(HOST_OS_FUCHSIA)
 
 #include "bin/eventhandler.h"
@@ skipping 419 matching lines @@
     } else {
       ASSERT(new_mask == 0);
       socket_map_.Remove(GetHashmapKeyFromFd(fd), GetHashmapHashFromFd(fd));
       di->Close();
       delete di;
       socket->SetClosedFd();
     }
     if (port != 0) {
       const bool success = DartUtils::PostInt32(port, 1 << kDestroyedEvent);
       if (!success) {
-        LOG_ERR("Failed to post destroy event to port %ld\n", port);
+        LOG_INFO("Failed to post destroy event to port %ld\n", port);
       }
     }
   } else if (IS_COMMAND(msg->data, kReturnTokenCommand)) {
     const int count = TOKEN_COUNT(msg->data);
     const intptr_t old_mask = di->Mask();
     LOG_INFO("\t Return Token: %ld: %lx\n", fd, old_mask);
     di->ReturnTokens(msg->dart_port, count);
     UpdatePort(old_mask, di);
   } else if (IS_COMMAND(msg->data, kSetEventMaskCommand)) {
     // `events` can only have kInEvent/kOutEvent flags set.
@@ skipping 34 matching lines @@
     di->NotifyAllDartPorts(event_mask);
   } else if (event_mask != 0) {
     event_mask = di->io_handle()->ToggleEvents(event_mask);
     if (event_mask != 0) {
       Dart_Port port = di->NextNotifyDartPort(event_mask);
       ASSERT(port != 0);
       bool success = DartUtils::PostInt32(port, event_mask);
       if (!success) {
         // This can happen if e.g. the isolate that owns the port has died
         // for some reason.
-        LOG_ERR("Failed to post event to port %ld\n", port);
+        LOG_INFO("Failed to post event to port %ld\n", port);
       }
     }
   }
   UpdatePort(old_mask, di);
 }
 
 
 int64_t EventHandlerImplementation::GetTimeout() const {
   if (!timeout_queue_.HasTimeout()) {
     return kInfinityTimeout;
@@ skipping 76 matching lines @@
   // The hashmap does not support keys with value 0.
   return dart::Utils::WordHash(fd + 1);
 }
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(HOST_OS_FUCHSIA)
 
 #endif  // !defined(DART_IO_DISABLED)