Change WebLayer::addAnimation to transfer ownership of WebAnimation.

Source/core/platform/graphics/GraphicsLayer.h

Index: Source/core/platform/graphics/GraphicsLayer.h
diff --git a/Source/core/platform/graphics/GraphicsLayer.h b/Source/core/platform/graphics/GraphicsLayer.h
index 3960cf1142ea456df204684a05ab163245cd8568..1870c88ace69138548134a84a30c651b18382377 100644
--- a/Source/core/platform/graphics/GraphicsLayer.h
+++ b/Source/core/platform/graphics/GraphicsLayer.h
@@ -225,7 +225,7 @@ public:
     // Return true if the animation is handled by the compositing system. If this returns
     // false, the animation will be run by AnimationController.
     // These methods handle both transitions and keyframe animations.
-    bool addAnimation(WebKit::WebAnimation*);
+    bool addAnimation(PassOwnPtr<WebKit::WebAnimation>);
     void pauseAnimation(int animationId, double /*timeOffset*/);
     void removeAnimation(int animationId);