WIP: WebLayer::addAnimation should transfer the ownership of WebAnimation instance.

Source/core/platform/graphics/GraphicsLayer.cpp

Index: Source/core/platform/graphics/GraphicsLayer.cpp
diff --git a/Source/core/platform/graphics/GraphicsLayer.cpp b/Source/core/platform/graphics/GraphicsLayer.cpp
index 6bae3b2b6188dfe0bdf56538530d2ae3c76a3c06..9006a21af071cbaa8d80c8d8bf9680ff6592b058 100644
--- a/Source/core/platform/graphics/GraphicsLayer.cpp
+++ b/Source/core/platform/graphics/GraphicsLayer.cpp
@@ -1000,7 +1000,7 @@ bool GraphicsLayer::addAnimation(const KeyframeValueList& values, const IntSize&
 
         // Remove any existing animations with the same animation id and target property.
         platformLayer()->removeAnimation(animationId, toAdd->targetProperty());
-        return platformLayer()->addAnimation(toAdd.get());
+        return platformLayer()->addAnimation(toAdd.release());
     }
 
     return false;