[gin] Turn gin into a component

This will allow for using gin from content and blink at the same time in
a component build

BUG=321631
R=abarth@chromium.org,aa@chromium.org

Review URL: https://codereview.chromium.org/101583004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240425 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240425