Revert "clang: Makes builds with clang less dependent on absolute file path"

This reverts commit fdca0741b22a4dddbf1808b8d0081651662b22c5.

This seems to break codesearch grok indexing.

BUG=580103
TBR=brettw

Review URL: https://codereview.chromium.org/1620583002

Cr-Commit-Position: refs/heads/master@{#370919}
5 files changed