substitute chromium of distro with the latest build

prepare_chromium.sh

# Credit goes to saiarcot895:
#   https://launchpad.net/~saiarcot895/+archive/ubuntu/chromium-dev
# Assuming API key has been generated, 
#   http://www.chromium.org/developers/how-tos/api-keys
# and (of course), chromium-browser has installed...
sudo mv $(which chromium-browser) $(which chromium-browser).backup

git clone https://github.com/scheib/chromium-latest-linux.git
sudo ln -s $(pwd)/chromium-latest-linux/latest/chrome $(which chromium-browser)

echo '# added for using latest chromium-browser' >> ~/.profile
echo '# https://launchpad.net/~saiarcot895/+archive/ubuntu/chromium-dev' >> ~/.profile
echo 'export GOOGLE_API_KEY="api_key"' >> ~/.profile
echo 'export GOOGLE_DEFAULT_CLIENT_ID="client_id"' >> ~/.profile
echo 'export GOOGLE_DEFAULT_CLIENT_SECRET="client_secret"' >> ~/.profile
nano ~/.profile