Source/WebCore: Sideways 'wobble' when scrolling with trackpad on Mavericks

Source/WebCore: Sideways 'wobble' when scrolling with trackpad on Mavericks
https://bugs.webkit.org/show_bug.cgi?id=127521
-and corresponding-
<rdar://problem/14137306>

Reviewed by Simon Fraser.

This patch takes http://trac.webkit.org/changeset/154535 which introduced
filtering wheel events for overflow areas to try to make them less sensitive to X
deltas when scrolling in a primarily Y direction, and it factors that code out
into its own class, now called WheelEventDeltaTracker. So now this new class can
use the same code to filter events for WebKit2’s EventDispatcher.

Files for WheelEventDeltaTracker.
* CMakeLists.txt:
* GNUmakefile.list.am:
* WebCore.vcxproj/WebCore.vcxproj:
* WebCore.vcxproj/WebCore.vcxproj.filters:
* WebCore.xcodeproj/project.pbxproj:

WK2 needs these new WheelEventDeltaTracker functions.
* WebCore.exp.in:

Move a bunch of code over to WheelEventDeltaTracker and use
m_recentWheelEventTracker to serve the same purpose.
* page/EventHandler.cpp:
(WebCore::EventHandler::EventHandler):
(WebCore::EventHandler::handleWheelEvent):
(WebCore::EventHandler::defaultWheelEventHandler):
* page/EventHandler.h:

Allow horizontal rubber banding now that we have some event filtering in place.
* page/FrameView.cpp:
(WebCore::FrameView::FrameView):

New files. Most of this code was from EventHandler.
* page/WheelEventDeltaTracker.cpp: Added.
(WebCore::WheelEventDeltaTracker::WheelEventDeltaTracker):
(WebCore::WheelEventDeltaTracker::~WheelEventDeltaTracker):
(WebCore::WheelEventDeltaTracker::beginTrackingDeltas):
(WebCore::WheelEventDeltaTracker::endTrackingDeltas):
(WebCore::WheelEventDeltaTracker::recordWheelEventDelta):
(WebCore::deltaIsPredominantlyVertical):
(WebCore::WheelEventDeltaTracker::dominantScrollGestureDirection):
* page/WheelEventDeltaTracker.h: Added.
(WebCore::WheelEventDeltaTracker::isTrackingDeltas):

New function to clone events while zero-ing out certain deltas.
* platform/PlatformWheelEvent.h:
(WebCore::PlatformWheelEvent::copyIgnoringHorizontalDelta):
(WebCore::PlatformWheelEvent::copyIgnoringVerticalDelta):

Source/WebKit2: Sideways 'wobble' when scrolling with trackpad on Mavericks
https://bugs.webkit.org/show_bug.cgi?id=127521
-and corresponding-
<rdar://problem/14137306>

Reviewed by Simon Fraser.

Start using WebCore::WheelEventDeltaTracker to filter events.
* WebProcess/WebPage/EventDispatcher.cpp:
(WebKit::EventDispatcher::EventDispatcher):
(WebKit::EventDispatcher::wheelEvent):
* WebProcess/WebPage/EventDispatcher.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@163180 268f45cc-cd09-0410-ab3c-d52691b4dbfc