Debugging Flash Player with Firebug and Chrome
If you’ve ever used Firebug to debug Flash and Flex applications in a browser, consider using Danny Patterson’s FirebugTarget class instead. It hooks into the Flex Logging API, so the debug statements are omitted when you export a release build.
I also discovered that you don’t need Firebug and Firefox to take advantage of it: Google Chrome also has a JavaScript console. Simply choose Developer > JavaScript console, or press Ctrl+Shift+J on Windows. The JavaScript console opens in a new browser window. Very handy.
You even get different icons for error and warn. Just remember to open the JavaScript console after you’ve loaded your app in Google Chrome.