GitLab

This changes the current directory for script execution to be the build directory rather than the current BUILDfile directory. This makes things more consistent and simplifies some implementation.

It adds a new function to_build_path() for buildfiles to convert files to the build directory for this kind of call.

I removed all of the built-in relative* variables that were required to support this, and added one for target_out_dir and root_out_dir.

I added some tests and a test helper object since I was doing this kind of Scope setup a lot.

R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/23606031

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@223622 0039d316-1c4b-4281-b951-d872f2087c98