Revert "Make RelativePath use abspath rather than realpath for the 'path' variable."

Revert "Make RelativePath use abspath rather than realpath for the 'path' variable."

This reverts commit 121d89dfcd4f6ebe1c89524b3f9ca11ddd437e77.

R=dpranke@chromium.org

> Make RelativePath use abspath rather than realpath for the 'path' variable.
> This allows gyp to work correctly in symlink-heavy environments. Basically,
> this is because gyp paths need to be in a consistent tree, so we need to
> compute a path to the target within the *stated* tree, even if it is not
> the real underlying path to the target. The 'relative_path' variable does
> need to be resolved using realpath, since gyp or the underlying build system
> might cd to it before looking for the 'path' target.
>
> Also make Ninja's host configuration consult environment variables analogous
> to those it previously had for the target configuration, and replace os.getenv
> with os.environ.get for consistency.
>
> R=thakis@chromium.org

BUG=

Committed: https://chromium.googlesource.com/external/gyp/+/5d01a8cda53bfa23f1dcbe0c31c33aa30f50cf4c

[bradn, 2015-09-04 19:39:00]

bradnelson@google.com changed reviewers:
+ dpranke@chromium.org
- lindleyf@google.com, thakis@chromium.org, titzer@chromium.org

[Dirk Pranke, 2015-09-04 19:56:42]

lgtm

[bradn, 2015-09-04 19:58:51]

Committed patchset #1 (id:1) manually as
5d01a8cda53bfa23f1dcbe0c31c33aa30f50cf4c (presubmit successful).

[kjellander_chromium, 2015-09-07 06:05:41]

On 2015/09/04 19:58:51, bradn wrote:
> Committed patchset #1 (id:1) manually as
> 5d01a8cda53bfa23f1dcbe0c31c33aa30f50cf4c (presubmit successful).

I created a roll CL to pick this up in
https://codereview.chromium.org/1304983008