Change DEPS to point at upstream, not chromium's fork.
`skia_use_icu` defaults to true everywhere but iOS
Clean up SkLoadICU: use U_ICUDATA_ENTRY_POINT, no DLL.
Add data dep to icu/icu.gni
Scripts: icu/{make_data_assembly.py,make_data_obj_win.py}
Scripts: icu/{update_icu.sh,build_icu_data_file.py} for rebuilding
document process in icu/README.md
Bug: skia:8702
Change-Id: I99789749ba84ae737f6c62475d0d676cd36715bb
Reviewed-on: https://skia-review.googlesource.com/c/186870
Commit-Queue: Hal Canary <halcanary@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>