android envsetup: Don't set script-local variable toolchain_dir.

Unused after r250141. No behavior change.

BUG=330631
TBR=torne@chromium.org

Review URL: https://codereview.chromium.org/159133002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250187 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250187
Add support for importing other modules to mojom.

You can address types like namespace.Type, and constants like
namespace.CONSTANT.

BUG=325500
R=darin@chromium.org

Review URL: https://codereview.chromium.org/149663004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250188 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250188