By the way, the nginx wiki says that you should avoid ifs when possible: http://wiki.nginx.org/IfIsEvil

Wouldn't something like this accomplish the same thing? (Sorry if I'm totally wrong, I'm not really good)

   location /google/ {

   }
   location /y_key_/ {

   }
   location ~ \.html$ {
      return 404;
   }
   location = /index {
      return 404;
   }
   location / {
      try_files $uri @rewrite
   }
   location @rewrite {
      rewrite ^/$ /index.html break;
      rewrite .* $uri.html break;
   }