Revert "Drag image for text-area should contain text of text-area (#13557)"

This reverts commit f227f0c1068f17e5491bd399d9f5bde16a0c8272.

Synchronising content after IE wraps the given element into a table with
a body causes a NullPointerException on client side. 

This patch also contains new API and should be targeted to master branch.

Change-Id: Ia19acd9fa31c7b67507bf797a2bab7c28ea37b4b