Make build-bisect script work on win.
Make build-bisect script work on win.

Unzip using python rather than using the unzip command which might not be
available on windows.

TEST=NONE
BUG=NONE

Review URL: http://codereview.chromium.org/1549006

git-svn-id: http://src.chromium.org/svn/trunk/src@43160 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 228d3a7e73b3051e25350a9f78337c76fc9238c9
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser