Have Frame::animation() return a reference

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index 20758d6302e58c67e25ae31d5a983fc8681fdbb5..8e089f087c2085c00c117e2f2047c1764a168dac 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -588,7 +588,7 @@ TransformationMatrix RenderLayer::currentTransform(RenderStyle::ApplyTransformOr
 
     if (renderer()->style()->isRunningAcceleratedAnimation()) {
         TransformationMatrix currTransform;
-        RefPtr<RenderStyle> style = renderer()->animation()->getAnimatedStyleForRenderer(renderer());
+        RefPtr<RenderStyle> style = renderer()->animation().getAnimatedStyleForRenderer(renderer());
         style->applyTransform(currTransform, renderBox()->pixelSnappedBorderBoxRect().size(), applyOrigin);
         makeMatrixRenderable(currTransform, canRender3DTransforms());
         return currTransform;
@@ -4265,7 +4265,7 @@ inline bool RenderLayer::needsCompositingLayersRebuiltForFilters(const RenderSty
     if (!hasOrHadFilters(oldStyle, newStyle))
         return false;
 
-    if (renderer()->animation()->isRunningAcceleratedAnimationOnRenderer(renderer(), CSSPropertyWebkitFilter)) {
+    if (renderer()->animation().isRunningAcceleratedAnimationOnRenderer(renderer(), CSSPropertyWebkitFilter)) {
         // When the compositor is performing the filter animation, we shouldn't touch the compositing layers.
         // All of the layers above us should have been promoted to compositing layers already.
         return false;
@@ -4301,7 +4301,7 @@ void RenderLayer::updateFilters(const RenderStyle* oldStyle, const RenderStyle*
     updateOrRemoveFilterClients();
     // During an accelerated animation, both WebKit and the compositor animate properties.
     // However, WebKit shouldn't ask the compositor to update its filters if the compositor is performing the animation.
-    bool shouldUpdateFilters = compositedLayerMapping() && !renderer()->animation()->isRunningAcceleratedAnimationOnRenderer(renderer(), CSSPropertyWebkitFilter);
+    bool shouldUpdateFilters = compositedLayerMapping() && !renderer()->animation().isRunningAcceleratedAnimationOnRenderer(renderer(), CSSPropertyWebkitFilter);
     if (shouldUpdateFilters)
         compositedLayerMapping()->updateFilters(renderer()->style());
     updateOrRemoveFilterEffectRenderer();