Have Frame::animation() return a reference

Source/core/css/CSSComputedStyleDeclaration.cpp

Index: Source/core/css/CSSComputedStyleDeclaration.cpp
diff --git a/Source/core/css/CSSComputedStyleDeclaration.cpp b/Source/core/css/CSSComputedStyleDeclaration.cpp
index 76d40ffcf256bc3f2a207dca4866c1ec73f719b2..6e180b0646d7d22df8e9164d1e425ceb1410e3ac 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.cpp
+++ b/Source/core/css/CSSComputedStyleDeclaration.cpp
@@ -1623,9 +1623,9 @@ PassRefPtr<RenderStyle> CSSComputedStyleDeclaration::computeRenderStyle(CSSPrope
         AnimationUpdateBlock animationUpdateBlock(renderer->animation());
         if (m_pseudoElementSpecifier && !styledNode->isPseudoElement()) {
             // FIXME: This cached pseudo style will only exist if the animation has been run at least once.
-            return renderer->animation()->getAnimatedStyleForRenderer(renderer)->getCachedPseudoStyle(m_pseudoElementSpecifier);
+            return renderer->animation().getAnimatedStyleForRenderer(renderer)->getCachedPseudoStyle(m_pseudoElementSpecifier);
         }
-        return renderer->animation()->getAnimatedStyleForRenderer(renderer);
+        return renderer->animation().getAnimatedStyleForRenderer(renderer);
     }
     return styledNode->computedStyle(styledNode->isPseudoElement() ? NOPSEUDO : m_pseudoElementSpecifier);
 }