GN: Normalize the build directory path

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}

[hashimoto, 2016-02-18 09:37:06]

hashimoto@chromium.org changed reviewers:
+ brettw@chromium.org

[hashimoto, 2016-02-18 09:37:06]

Thank you for taking care of the revert and your insightful advise.
This time the input path is always a full path so hopefully nothing will go
wrong.

As far as I tested, "gn gen" works well with --root=<symlink> and "//<symlink>"
as the build path.

[brettw, 2016-02-18 21:52:38]

The CQ bit was checked by brettw@chromium.org

[brettw, 2016-02-18 21:52:38]

lgtm

[commit-bot: I haz the power, 2016-02-18 21:57:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1707293002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1707293002/1

[commit-bot: I haz the power, 2016-02-18 22:11:10]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-18 22:13:21]

Description was changed from

==========
GN: Normalize the build directory path

BUG=586906
TEST=ln -s /tmp out_tmp && out/gn/gn gen //out_tmp/Release
==========

to

==========
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}
==========

[commit-bot: I haz the power, 2016-02-18 22:13:21]

Patchset 1 (id:??) landed as
https://crrev.com/62b5ce373ce17228a3c06f3e32ff329180e89921
Cr-Commit-Position: refs/heads/master@{#376288}

[hashimoto, 2016-02-22 09:39:36]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1723453002/ by hashimoto@chromium.org.

The reason for reverting is: Doesn't work when the build directory does not
exit..