Get rid of StorageTracker::setClient
https://bugs.webkit.org/show_bug.cgi?id=115376

Reviewed by Sam Weinig.

* WebCore.exp.in:
* storage/StorageTracker.cpp:
* storage/StorageTracker.h:
(StorageTracker):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149328 268f45cc-cd09-0410-ab3c-d52691b4dbfc