In SkRuntimeEffect, just use hash of SkSL as the ID

Change-Id: I2ce210889452756d5d100fbb15f578bb72e2af2a
Bug: skia:9813
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/268687
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
8 files changed