Crash when trying to determine the length of an invalid message
https://bugs.webkit.org/show_bug.cgi?id=115127
<rdar://problem/13700736>

Reviewed by Beth Dakin.

Use message instead of incomingMessage since incomingMessage will always be null.

* Platform/CoreIPC/Connection.cpp:
(CoreIPC::Connection::processIncomingMessage):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149064 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Fix a merge error in r149007 (was missing a null check added in r148777).

* rendering/LogicalSelectionOffsetCaches.h:
(WebCore::containingBlockForAbsolutePosition):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149065 268f45cc-cd09-0410-ab3c-d52691b4dbfc
Vertical overlay scrollbar in iframes fades in and out rapidly when you scroll in 
a circle
https://bugs.webkit.org/show_bug.cgi?id=115124
-and corresponding-
<rdar://problem/13168957>

Reviewed by Anders Carlsson.

With http://trac.webkit.org/changeset/119834 we started calling 
ScrollbarPainterController's contentAreaScrolled/contentAreaScrolledInDirection 
API on a zero-delay timer instead of calling it right away. This prevented some 
crashes that we saw whenever this was called during a layout. However, that delay, 
combined with the particulars of contentAreaScrolledInDirection cause this bug 
where sometimes the scrollbars in an iframe will fade out very noticeably when 
scrolling in a circle.

This change makes it so we will only use the zero-delay timer if the 
ScrollableArea is not currently handling a wheel event. If it IS handling a wheel 
event, then we will send the notifications to AppKit right away. I confirmed that 
this change did not reintroduce the old crashes. 

Keep track of whether we are currently handling a wheel event with the new member 
variable m_isHandlingWheelEvent.
* page/EventHandler.cpp:
(WebCore::EventHandler::EventHandler):
(WebCore::EventHandler::handleWheelEvent):
* page/EventHandler.h:
(WebCore::EventHandler::isHandlingWheelEvent):
(EventHandler):

To prevent layering violations, the ScrollableArea sub-classes will have to access 
this information from the EventHandler.
* page/FrameView.cpp:
(WebCore::FrameView::isHandlingWheelEvent):
* page/FrameView.h:
* platform/ScrollableArea.h:
(WebCore::ScrollableArea::isHandlingWheelEvent):
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::isHandlingWheelEvent):
* rendering/RenderLayer.h:
(RenderLayer):
* rendering/RenderListBox.cpp:
(WebCore::RenderListBox::isHandlingWheelEvent):
* rendering/RenderListBox.h:

sendContentAreaScrolledSoon() can be private. Also add new function 
sendContentAreaScrolled().
* platform/mac/ScrollAnimatorMac.h:
(ScrollAnimatorMac):

If the ScrollableArea is handling a wheel event, call 
sendContentAreaScrolled(), otherwise call sendContentAreaScrolledSoon()
* platform/mac/ScrollAnimatorMac.mm:
(WebCore::ScrollAnimatorMac::notifyContentAreaScrolled):
(WebCore::ScrollAnimatorMac::sendContentAreaScrolled):

Re-factored to use sendContentAreaScrolled()
(WebCore::ScrollAnimatorMac::sendContentAreaScrolledTimerFired):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149066 268f45cc-cd09-0410-ab3c-d52691b4dbfc