[SPv2] Decomposite otherwise-compositable animations that paint nothing.

third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp

Index: third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
diff --git a/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp b/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
index ab03d70d7da505f70590c77e8ef86920724a91b1..71ba6619026c86a2b4fce59503256e9b4931ed3a 100644
--- a/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
+++ b/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
@@ -530,8 +530,10 @@ void SVGImage::serviceAnimations(double monotonicAnimationStartTime) {
   // PaintArtifactCompositor analysis of whether animations should be
   // composited.
   if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+    Optional<CompositorElementIdSet> compositedAnimationElementIds;
     DocumentAnimations::updateAnimations(frameView->layoutView()->document(),
-                                         DocumentLifecycle::LayoutClean);
+                                         DocumentLifecycle::LayoutClean,
+                                         compositedAnimationElementIds);
   }
 }