Revert "cloneNode: Change the default value back to false"

This reverts commit cecf04c882917694101b7447ca097f3460c4bc39.
The reason is that it breaks shadow dom.
Example: try load http://jsbin.com/UkiXAzO/1
If you see red "Hi!", then shadow dom works.

BUG=
TBR=arv@chromium.org

Review URL: https://codereview.chromium.org/35163002

git-svn-id: svn://svn.chromium.org/blink/trunk@160200 bbb929c8-8fbe-4397-9dbb-9b2b20218538