Fix a typo in SkISize comments

Change-Id: I94597214ea3c7e3c0b5f88c42378061f0d217da2
Reviewed-on: https://skia-review.googlesource.com/157400
Reviewed-by: Brian Osman <brianosman@google.com>
Auto-Submit: Nathan Rogers <nathanrogers@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
1 file changed