[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 064b9010b8c720d2e889a505fd3fa2f6b185da58..ff25b6d30b487d9a7e71a3d2fcfe7e846fe78bf9 100644
--- a/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
+++ b/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
@@ -585,8 +585,10 @@ void SVGImage::serviceAnimations(double monotonicAnimationStartTime) {
   // PaintArtifactCompositor analysis of whether animations should be
   // composited.
   if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+    Optional<CompositorElementIdSet> compositedElementIds;
     DocumentAnimations::updateAnimations(frameView->layoutView()->document(),
-                                         DocumentLifecycle::LayoutClean);
+                                         DocumentLifecycle::LayoutClean,
+                                         compositedElementIds);
   }
 }