Have Frame::animation() return a reference

Source/core/rendering/RenderLayerCompositor.cpp

Index: Source/core/rendering/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/RenderLayerCompositor.cpp b/Source/core/rendering/RenderLayerCompositor.cpp
index bdce2dbf707ee204d81b5ff5b8587397e8b3cb50..5848264a860d2e30c09868616488c93263a350af 100644
--- a/Source/core/rendering/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/RenderLayerCompositor.cpp
@@ -1999,10 +1999,7 @@ bool RenderLayerCompositor::requiresCompositingForAnimation(RenderObject* render
 {
     if (!(m_compositingTriggers & ChromeClient::AnimationTrigger))
         return false;
-
-    if (AnimationController* animController = renderer->animation())
-        return animController->isRunningAcceleratableAnimationOnRenderer(renderer);
-    return false;
+    return renderer->animation().isRunningAcceleratableAnimationOnRenderer(renderer);
 }
 
 bool RenderLayerCompositor::requiresCompositingForTransition(RenderObject* renderer) const
@@ -2189,11 +2186,7 @@ bool RenderLayerCompositor::isRunningAcceleratedTransformAnimation(RenderObject*
 {
     if (!(m_compositingTriggers & ChromeClient::AnimationTrigger))
         return false;
-
-    if (AnimationController* animController = renderer->animation())
-        return animController->isRunningAnimationOnRenderer(renderer, CSSPropertyWebkitTransform);
-
-    return false;
+    return renderer->animation().isRunningAnimationOnRenderer(renderer, CSSPropertyWebkitTransform);
 }
 
 // If an element has negative z-index children, those children render in front of the