Google HR (or a third-party headhunter associated with Google) contacted me through LinkedIn and asked for my CV as well as a get-to-know phone call.

Then, they arranged a technical phone interview for me.

They were quite generous in allowing me to delay it until a month later, so that I had more time to prepare, since the software engineer position was not a 100% fit for my area.

This is a pretty standard string search. Given a text message containing people's names (a name can be one, two, three, or more words). Since each person has a Google+ profile page, the request is to go through the text message and replace all the people's names with their Google+ pages.