Prior to this change, we were creating the SkSL variable and declaration
immediately on DSLVar creation. This causes problems with function
parameters, which are sometimes supposed to be tagged
SK_MAIN_COORDS_BUILTIN. If we have already created the variable and
inserted it into the symbol table, then by the time we determine the
variable is supposed to be SK_MAIN_COORDS_BUILTIN, it is too late to
modify the (now-const) variable.
We are not yet doing this tagging, but refactoring the creation in this
fashion paves the way to making it possible.
Change-Id: I031170502c5e7c1fff5ecfac01bea470ff4e61ce
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/389216
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
707d31578c