Move remaining IDB unit tests from web/tests/ to modules/indexeddb/

R=alecflett@chromium.org,jamesr@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19771014

git-svn-id: svn://svn.chromium.org/blink/trunk@155128 bbb929c8-8fbe-4397-9dbb-9b2b20218538