PlatformWheelEvent should know about the scroll phase on the Mac

Reviewed by Anders Carlsson.

Source/WebCore: 

Add a phase parameter on Mac PlatformWheelEvents.

* platform/PlatformWheelEvent.h:
(WebCore::PlatformWheelEvent::PlatformWheelEvent):
(WebCore::PlatformWheelEvent::phase):
* platform/mac/WheelEventMac.mm:
(WebCore::phaseForEvent):
(WebCore::PlatformWheelEvent::PlatformWheelEvent):

WebKit2: 

Add a phase parameter on Mac WebWheelEvent and pipe it down to PlatformWheelEvent.

* Shared/WebEvent.h:
(WebKit::WebWheelEvent::phase):
* 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::WebEventFactory::createWebWheelEvent):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@75661 268f45cc-cd09-0410-ab3c-d52691b4dbfc