Unreviewed, rolling out r140171.
http://trac.webkit.org/changeset/140171
https://bugs.webkit.org/show_bug.cgi?id=107193

Regressed scrollable region size in other cases.

Source/WebCore:

* rendering/RenderBlock.cpp:
(WebCore::RenderBlock::simplifiedLayout):

LayoutTests:

* fast/overflow/height-during-simplified-layout-expected.txt: Removed.
* fast/overflow/height-during-simplified-layout.html: Removed.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140482 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Prevent race condition during Worker shutdown
https://bugs.webkit.org/show_bug.cgi?id=107577

Reviewed by Dmitry Titov.

Source/WebCore:

During worker shutdown, from the main thread a cleanup task is posted followed by
terminating the message queue, which prevents further tasks from being processed. It was
possible for another task be posted by another thread between the main thread calls
to postTask and terminate(), which would cause that task to run after cleanup. Expose
a new WTF::MessageQueue::appendAndKill() method which keeps a mutex around the two steps,
and use that during worker shutdown.

No reliable tests for the race - problem identified by inspection of user crash stacks.

* workers/WorkerRunLoop.cpp:
(WebCore::WorkerRunLoop::postTaskAndTerminate): New method, uses MessageQueue::appendAndKill()
* workers/WorkerRunLoop.h:
* workers/WorkerThread.cpp:
(WebCore::WorkerThread::stop): Uses postTaskAndTerminate() to avoid race.

Source/WTF:

Add MessageQueue::appendAndKill() which wraps those two steps with a mutex so other
threads can't sneak a message in between.

* wtf/MessageQueue.h: Added appendAndKill() method.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140483 268f45cc-cd09-0410-ab3c-d52691b4dbfc