https://bugs.webkit.org/show_bug.cgi?id=127034

Reviewed by Andreas Kling.

We have some cases where getting computed style leads to crashes in loadPendingImages. 
This is probably caused by load callbacks resulting in re-entering WebKit and killing the StyleResolver.
        
As a speculative fix suspend resource loads (and so callbacks) when getting the computed style.
We do similar suspension during style recalc for the same reason.

* dom/Document.cpp:
(WebCore::Document::styleForElementIgnoringPendingStylesheets):
* loader/ResourceLoadScheduler.h:
(WebCore::ResourceLoadScheduler::Suspender::Suspender):
(WebCore::ResourceLoadScheduler::Suspender::~Suspender):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@162063 268f45cc-cd09-0410-ab3c-d52691b4dbfc