Macro servoshell::desktop::tracing::trace_embedder_msg

macro_rules! trace_embedder_msg {
    ($event:expr, $($rest:tt)+) => { ... };
}

Log an event from servo (servo::embedder_traits::EmbedderMsg) at trace level.

• To disable tracing: RUST_LOG=‘servoshell<servo@=off’
• To enable tracing: RUST_LOG=‘servoshell<servo@’
• Recommended filters when tracing is enabled:
  • servoshell<servo@EventDelivered=off
  • servoshell<servo@ReadyToPresent=off