fixing gyp base_dir.
fixing gyp base_dir.

BUG=None
TEST=None
TBR=iannucci@chromium.org

Review URL: https://codereview.chromium.org/946433002

git-svn-id: 239fca9b83025a0b6f823aeeca02ba5be3d9fd76@294134 0039d316-1c4b-4281-b951-d872f2087c98

eunchong/build,eunchong/build,eunchong/build,eunchong/build