Drop obsolete SK_CRASH and SK_DEBUGBREAK macros

The SK_CRASH and SK_DEBUGBREAK macros are no longer used by Skia, so
there's no point in continuing to define them in SkUserConfig.h.

There were a couple of references to SK_CRASH in //src/skia/ext; I've
replaced them with equivalent CHECKs.

Some other changes:

* Refreshes skia/config/SkUserConfig.h from third_party/skia
* Drops the now always-false |fatal| parameter in SkDebugf_FileLine
* Consolidates customizations after the "Chrome-specific" line

The changes pulled from third_party/skia's SkUserConfig.h mostly are
comments and formatting, and should have no effect.

Similar to https://pdfium-review.googlesource.com/c/pdfium/+/54650, but
for Chromium instead of PDFium.

The PDFium copy of SkUserConfig.h tries to minimize lint errors, while
the Chromium copy tries to preserve the original formatting, so unlike
the PDFium change, I haven't tried to fix lint errors.

Change-Id: Ieb66af9e2f30a36a19184451966f9a85f2a10997
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1618148
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: K Moon <kmoon@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661372}
4 files changed