Move uils and sksl to a common sources GYP file.

This is for the coalescing of sources in one GYP file to improve GN runtime. If
this is successful, the other sources lists will also be merged into this one
file.

Inlines "../src" and "../include" for skia_source_dir and skia_include_dir. Evaluating these with GYP's variable expansion is annoying since I think another layer of nesting is required. Coding these explicitly is also more clear. This used to be required because Chromium would reference these .gypi files directly with a different path, but this no longer happens.

Removes the chromium defines gypi which is no longer referenced.

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2302723005

Review-Url: https://codereview.chromium.org/2302723005
8 files changed