The bulk of this commit was generated by running:
run-clang-tidy.py \
-checks='-*,llvm-namespace-comment' \
-header-filter=^/.../mozilla-central/.* \
-fix
This patch was generated with the following command:
find . -name "*.h" -o -name "*.cpp" | xargs perl -pi -e 's/return ([a-zA-Z0-9]+)\.ErrorCode\(\);/return \1.StealNSResult();/'