message: Metal: Fix Device::pendingCommands being freed under us
diff: @@ -202,6 +202,7 @@ namespace metal {
  id<MTLCommandBuffer> Device::GetPendingCommandBuffer() {
  if (pendingCommands == nil) {
  pendingCommands = [commandQueue commandBuffer];
  + [pendingCommands retain];
  }
  return pendingCommands;
  }
  @@ -220,6 +221,7 @@ namespace metal {
  }];
  [pendingCommands commit];
  + [pendingCommands release];
  pendingCommands = nil;
  pendingCommandSerial ++;
  }
  