Add phase in addition to momentumPhase to platform wheel events

Add phase in addition to momentumPhase to platform wheel events
Part of <rdar://problem/8945362>

Reviewed by Anders Carlsson.

Rename existing phase to momentumPhase.

../WebCore:

* platform/PlatformWheelEvent.h:
(WebCore::PlatformWheelEvent::PlatformWheelEvent):
(WebCore::PlatformWheelEvent::momentumPhase):
* platform/mac/ScrollAnimatorMac.mm:
(WebCore::ScrollAnimatorMac::handleWheelEvent):
(WebCore::ScrollAnimatorMac::smoothScrollWithEvent):
* platform/mac/WheelEventMac.mm:
(WebCore::momentumPhaseForEvent):
(WebCore::phaseForEvent):
(WebCore::PlatformWheelEvent::PlatformWheelEvent):

../WebKit2:

* Shared/WebEvent.h:
(WebKit::WebWheelEvent::momentumPhase):
* Shared/WebEventConversion.cpp:
(WebKit::WebKit2PlatformWheelEvent::WebKit2PlatformWheelEvent):
* Shared/WebWheelEvent.cpp:
(WebKit::WebWheelEvent::WebWheelEvent):
(WebKit::WebWheelEvent::encode):
(WebKit::WebWheelEvent::decode):
* Shared/mac/WebEventFactory.mm:
(WebKit::phaseForEvent):
(WebKit::momentumPhaseForEvent):
(WebKit::WebEventFactory::createWebWheelEvent):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@79141 268f45cc-cd09-0410-ab3c-d52691b4dbfc