(I only added the .rb for syntax highlighting)

reload.watchr.rb

watch (/(.*)(?:\.sass$|\.haml$|\.erb$)/) do |filename|
  puts "Changed: #{filename}"
  system %q{osascript -e "tell application \"Google Chrome\"
    tell active tab of first window
      execute javascript \"window.location.reload()\"
    end tell
  end tell"}
end