I don't have reliable information on a "Granger Whitelaw" — no prominent public figure, historical figure, or notable professional by that exact name comes up in what I can draw on. It's possible the name is:
- A private individual (not publicly notable)
- A near-miss for a similar name (e.g., George E. P. Whitelaw, a Los Angeles contractor and longtime figure in civic and political circles, is the closest match I can think of — if this is who you mean, let me know)
- A character from a book, show, or game I'm not placing correctly
Tell me a bit about the context — profession, era, where you saw the name — and I'll either confirm the match or dig further. A quick web search will narrow it fast if you'd like me to run one.