It isn't Google's job to feel guilty for the lack of qualified black tech workers. Universities these days are falling down over themselves trying to be inclusive, promote diversity, etc.; promising black students in technical fields are highly sought after... yet there are almost none of them. I'm in computational physics, not in computer engineering, so it's a slightly different field. However, the university I'm at now is extremely diversity-promoting -- and located in a city that is ~50% black... and there is one black physicist there. She's not African-American, either; she's Ethiopian (and competent as all hell, and headed for industry). At my previous university, there were folks from all around the world: a few Afrikaaners, Dutch, Russians, Germans, Brazilians, French, Chinese, Indians, Native Americans, Koreans, Mexicans, and so on... and no black folks at all. At the physics and astronomy conferences I go to, there are almost no black people. Yes, this is physics, not tech engineering, but I imagine the situation is about the same there.
For whatever reason, blacks (and especially African-Americans) are underrepresented in the tech sector. This is definitely worth some concern: it could be for innocent reasons, it could be for ones that need to be addressed (having to do with substandard schools in black areas, for instance), but whatever it is it's not Google's problem. By all means, let's make sure tech classes in black schools are up to standard, but it's not Google's job to worry about this.
Forcing Google at Al Sharpton-point to seek out and hire black folks, regardless of whether they are able to do their jobs well or not, is only going to make things worse, as people will ask "Is that guy over there able to do his job, or is he a quota hire?"