A page containing multiparts with "multipart/x-mixed-replace" should not be cached.

A page containing multiparts with "multipart/x-mixed-replace" should not be cached.
https://bugs.webkit.org/show_bug.cgi?id=82291

Patch by Chris Guan <chris.guan@torchmobile.com.cn> on 2012-03-27
Reviewed by Rob Buis.

If we have a multiPart reponse with multipart/x-mixed-replace,
the current page should not be cached. I use isMultipartPayload()
API which was supposed to be set in NetworkJob to decide to
cache page or not.

* WebCoreSupport/FrameLoaderClientBlackBerry.cpp:
(WebCore::FrameLoaderClientBlackBerry::canCachePage):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@112252 268f45cc-cd09-0410-ab3c-d52691b4dbfc