Revert of Un-nest configs in GN files. (patchset #3 id:40001 of...

Revert of Un-nest configs in GN files. (patchset #3 id:40001 of https://codereview.chromium.org/1318823008/ )

Reason for revert:
This breaks why these configs exist in the first place and seriously breaks the clang/win gn build (which is what these configs exist for).

Original issue's description:
> Un-nest configs in GN files.
>
> People sometimes nest targets or configs, usually with the assumption that this limits the visibility of a config to within a target. But this nesting provides no visibility restrictions over declaring it outside of a block.
>
> Un-nest for clarity.
>
> Committed: https://crrev.com/4af2eac8e84692d94f88504ab6e0b244b88dddcb
> Cr-Commit-Position: refs/heads/master@{#346461}

TBR=dpranke@chromium.org,brettw@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1316843006

Cr-Original-Commit-Position: refs/heads/master@{#346695}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 0cb5abbf230f3c30e3499d4e787f059ed723dd3c