Add project declaration for CMake

Change-Id: I8a544fa91d2fba957dceb9e6b2a60ea824780e48
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/244096
Commit-Queue: Herb Derby <herb@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
1 file changed