[GTK][AC] GraphicsLayerActor code clean up after clutter version up.

[GTK][AC] GraphicsLayerActor code clean up after clutter version up.
https://bugs.webkit.org/show_bug.cgi?id=109304

Patch by ChangSeok Oh <shivamidow@gmail.com> on 2013-02-08
Reviewed by Gustavo Noronha Silva.

This patch cleans up GraphicsLayerActor functions by using new clutter apis
and makes existing functions simple & readable.

No new tests since no change in functionality

* platform/graphics/clutter/GraphicsLayerActor.cpp:
(_GraphicsLayerActorPrivate):
(graphicsLayerActorApplyTransform):
(graphicsLayerActorPaint):
(graphicsLayerActorDraw):
(graphicsLayerActorUpdateTexture):
(drawLayerContents):
(graphicsLayerActorNew):
(graphicsLayerActorInvalidateRectangle):
(graphicsLayerActorSetTransform):
(graphicsLayerActorSetAnchorPoint):
(graphicsLayerActorGetAnchorPoint):
(graphicsLayerActorSetScrollPosition):
* platform/graphics/clutter/PlatformClutterAnimation.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@142297 268f45cc-cd09-0410-ab3c-d52691b4dbfc