Revert of GN: Normalize the build directory path (patchset #1 id:1 of https://codereview.chromium.org/1707293002/ )
Revert of GN: Normalize the build directory path (patchset #1 id:1 of https://codereview.chromium.org/1707293002/ )

Reason for revert:
Doesn't work when the build directory does not exit.

Original issue's description:
> GN: Normalize the build directory path
>
> BUG=586906
> TEST=ln -s /tmp out_tmp && out/gn/gn gen //out_tmp/Release
>
> Committed: https://crrev.com/62b5ce373ce17228a3c06f3e32ff329180e89921
> Cr-Commit-Position: refs/heads/master@{#376288}

TBR=brettw@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=586906

Review URL: https://codereview.chromium.org/1723453002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#376710}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk