Revert 137939

Revert 137939
> Add support for tracking hit test rectangles to enable fast event rejection in the compositor
> https://bugs.webkit.org/show_bug.cgi?id=103914
> 
> Reviewed by James Robinson.
> 
> Source/WebCore:
> 
> Adding support for tracking hit test target regions for the purpose of performing initial hit testing
> in the compositor to avoid blocking scrolling on the main thread while waiting to hit test events that
> aren't occuring in regions with handlers. This is initially being done to avoid having to go to the main
> thread when scrolling by flicking on touch devices when the flick occurs outside a tracked touch event
> region. This patch includes the implementation to turn this on in Chromium.
> 
> To accomplish this goal, Document will now keep a counted hash set of nodes with touch event handlers
> instead of only an unsigned integer of the total count. ScrollingCoordinator then updates the compositor
> when new touch event handlers are registered or removed, or after layout much like how
> nonFastScrollableRegions are currently tracked.
> 
> This implementation will not properly update the hit test rects when the renderers are inside a sub-
> tree that scrolls.
> 
> This change was initially rolled out due to stale Node pointers in Document's touchEventTargets. This
> patch adds a callback to remove the Node from that structure to Node's destructor. This is covered
> by the touch-target-removed-crash.html test case which is also added.
> 
> Test: platform/chromium/fast/events/touch/compositor-touch-hit-rects.html
>       platform/chromium/fast/events/touch/touch-target-removed-crash.html
> 
> * dom/Document.cpp:
> (WebCore::Document::Document): Added a HashCountedSet of touch target nodes. Note: DOMWindow targets
> are stored as the Document they point to.
> (WebCore::Document::didAddTouchEventHandler): Changed to keep track of the handler instead of a count, and
> to update the ScrollingCoordinator with the change.
> (WebCore::Document::didRemoveTouchEventHandler): Ditto.
> * dom/Document.h:
> (WebCore::Document::hasTouchEventHandlers): It's no longer O(1) to get the count of touch handlers, so
> expose whether there are any or not.
> (WebCore::Document::touchEventTargets):
> * dom/Node.cpp:
> (WebCore::Node::didMoveToNewDocument):
> (WebCore::tryAddEventListener):
> (WebCore::tryRemoveEventListener):
> * history/CachedFrame.cpp:
> (WebCore::CachedFrameBase::restore):
> * html/HTMLInputElement.cpp:
> (WebCore::HTMLInputElement::~HTMLInputElement):
> (WebCore::HTMLInputElement::updateType):
> * page/DOMWindow.cpp:
> (WebCore::DOMWindow::addEventListener): Add the Document to the touch target set instead of DOMWindow.
> (WebCore::DOMWindow::removeEventListener):
> * page/EventHandler.cpp:
> (WebCore::EventHandler::handleTouchEvent):
> * page/Frame.cpp:
> (WebCore::Frame::setDocument):
> * page/scrolling/ScrollingCoordinator.cpp:
> (WebCore::ScrollingCoordinator::computeAbsoluteTouchEventTargetRects): Walk the renderers for event handler
> nodes and generate the absolute hit testing rects.
> * page/scrolling/ScrollingCoordinator.h:
> (WebCore::ScrollingCoordinator::setTouchEventTargetRectsChanged): Hook to pass along the hit test rects to
> the scrolling tree/compositor.
> (ScrollingCoordinator):
> * page/scrolling/chromium/ScrollingCoordinatorChromium.cpp:
> (WebCore::ScrollingCoordinatorChromium::frameViewLayoutUpdated):
> (WebCore::ScrollingCoordinatorChromium::setTouchEventTargetRectsChanged):
> (WebCore::ScrollingCoordinatorChromium::setNonFastScrollableRegion):
> (WebCore::ScrollingCoordinatorChromium::setTouchEventTargetRects):
> * page/scrolling/chromium/ScrollingCoordinatorChromium.h:
> (ScrollingCoordinatorChromium):
> * testing/Internals.cpp:
> (WebCore::Internals::touchEventHandlerCount): Changed to do the work to calculate the actual count since
> it's no longer stored as an int in Document.
> (WebCore::Internals::touchEventTargetClientRects):
> * testing/Internals.h:
> (Internals):
> * testing/Internals.idl:
> 
> Source/WebKit/chromium:
> 
> Enabling touch event target region tracking.
> 
> * features.gypi:
> * src/WebPluginContainerImpl.cpp:
> (WebKit::WebPluginContainerImpl::requestTouchEventType):
> (WebKit::WebPluginContainerImpl::~WebPluginContainerImpl):
> 
> LayoutTests:
> 
> * platform/chromium/fast/events/touch/compositor-touch-hit-rects-expected.txt: Added.
> * platform/chromium/fast/events/touch/compositor-touch-hit-rects.html: Added.
> * platform/chromium/fast/events/touch/touch-target-removed-crash-expected.txt: Added.
> * platform/chromium/fast/events/touch/touch-target-removed-crash.html: Added.
> 

TBR=leviw@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=138155