https://bugs.webkit.org/show_bug.cgi?id=69383

Reviewed by John Sullivan.

* platform/mac/ScrollAnimatorMac.h:
Add new ScrollElasticityControllerClient member functions.

* platform/mac/ScrollAnimatorMac.mm:
(WebCore::ScrollAnimatorMac::isHorizontalScrollerPinnedToMinimumPosition):
(WebCore::ScrollAnimatorMac::isHorizontalScrollerPinnedToMaximumPosition):
(WebCore::ScrollAnimatorMac::stretchAmount):
(WebCore::ScrollAnimatorMac::startSnapRubberbandTimer):
(WebCore::ScrollAnimatorMac::stopSnapRubberbandTimer):
Implement the new ScrollElasticityControllerClient member functions.

(WebCore::ScrollAnimatorMac::beginScrollGesture):
Move code into ScrollElasticityController::beginScrollGesture and call it directly.

* platform/mac/ScrollElasticityController.h:
Add new ScrollElasticityControllerClient member functions.

* platform/mac/ScrollElasticityController.mm:
(WebCore::reboundDeltaForElasticDelta):
(WebCore::ScrollElasticityController::beginScrollGesture):
Set up the scroll gesture state.

(WebCore::ScrollElasticityController::stopSnapRubberbandTimer):
New helper function.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@96663 268f45cc-cd09-0410-ab3c-d52691b4dbfc