The chromium DEPS file can refer to v8 git hashes now. These
are converted back into svn revision numbers for the v8
releases spreadsheet.

The DEPS file's quotation mark policy changed which affects
the regexp for retrieving the v8 revision ("->').

TEST=script_test.py
TEST=tools/push-to-trunk/releases.py -c /path/to/chromium/src --branch recent
R=hinoka@google.com

Review URL: https://codereview.chromium.org/500023003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23357 ce2b1a6d-e550-0410-aec6-3dcde31c8c00