* Fixed CompileExternalTwoByteSource: Registered resources should
     better still be alive when they are accessed.

   * Fixed ownership in cctest/test-api/VisitExternalStrings.

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/139923003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18971 ce2b1a6d-e550-0410-aec6-3dcde31c8c00