[BlackBerry] Take into account policy checks in ClipboardBlackBerry

[BlackBerry] Take into account policy checks in ClipboardBlackBerry
https://bugs.webkit.org/show_bug.cgi?id=82651

Reviewed by George Staikos.

Add policy checks in the methods we implemented.

Covered by existing tests.

* platform/blackberry/ClipboardBlackBerry.cpp:
(WebCore::ClipboardBlackBerry::clearData):
(WebCore::ClipboardBlackBerry::clearAllData):
(WebCore::ClipboardBlackBerry::getData):
(WebCore::ClipboardBlackBerry::setData):
(WebCore::ClipboardBlackBerry::types):
* platform/blackberry/ClipboardBlackBerry.h:
(WebCore::ClipboardBlackBerry::create):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@112870 268f45cc-cd09-0410-ab3c-d52691b4dbfc