Running this file update /Applications/Chromium.app to the latest Chromium build.

update-chromium-mac.rb

#!/usr/bin/env ruby

require "open-uri"

if ARGV.first
  build_id = ARGV.first
else
  build_id = open("http://commondatastorage.googleapis.com/chromium-browser-snapshots/Mac/LAST_CHANGE") { |data| data.read }
end
build_url = "http://commondatastorage.googleapis.com/chromium-browser-snapshots/Mac/#{build_id}/chrome-mac.zip"
local_file_path = "/tmp/chromium-#{build_id}.zip"
extract_path = "/tmp"

puts "The requested Chromium build is #{build_id}."
puts "-----------------------------------------"

unless File.exists?(local_file_path)
  puts "Fetching build archive"
  Kernel.system "wget --verbose #{build_url} -O #{local_file_path}" or exit
else
  puts "Using #{local_file_path} in cache."
end

puts "Unzipping archive to #{extract_path}"
Kernel.system "unzip -x #{local_file_path} -d #{extract_path}" or exit

puts "Replacing Chromium.app"
Kernel.system "rm -fr /Applications/Chromium.app" or exit
Kernel.system "mv #{extract_path}/chrome-mac/Chromium.app /Applications/Chromium.app" or exit

puts "Removing temporary files"
Kernel.system "rm -rf #{extract_path}/chrome-mac"

puts "/Applications/Chromium.app is now the Chromium build ##{build_id}!"