Expose GrContext::dump() when SK_ENABLE_DUMP_GPU is defined.

Change-Id: I499228454bc387de2c988b8f607320b7e5ea57b0
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/233557
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
10 files changed