Nice example, but...I work with graphics code a lot (I'm a game developer), as well as in tons of other domains. That operation wouldn't be worth the mental storage (and certainly not a key!) to memorize. I can't think of the last time I would have needed it. Maybe when getting a pair of function parameters in the wrong order?
The example you gave wouldn't ever be a program I'd write. Magic numbers? Hard-coded rendering? Rendering something that can't be edited by an artist? All bad. I understand that it's just an example, but can you come up with one that would be valid in production code?
I know you were looking for a simple example, but in addition to the comments others have made about syntax not being a big deal for an experienced developer, this looks like a helper operation for developers who are doing it wrong to begin with.
Aside from that, years of user-experience research shows that modal editors are worse than the alternative (if you can hit one key, that means you can't type text in that mode; sorry vim-lovers, but it's true).
Yes I tried your experiment, and I could get it down to 7 keystrokes in my editor. I type quickly, so that's a couple of seconds at most; less than a second if I'm in the zone. With how rarely I do that operation, I'd not bother trying to optimize it more (another comment mentioned premature optimization).
But if I did need to do it a lot, creating a new macro that did the right thing wouldn't be hard; in a couple minutes I could bind a simple version of the command to a key permanently. Also, if I were modifying many similar lines to change them, I have options: Refactoring tools (if we're talking a function signature change), simple keyboard macros, or smart multi-file search-and-replace regular expression conversions.
And all of this in a "text" editor with a low barrier to entry (unlike vim OR emacs) -- though one that understands some structure at least.