[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 f30cb10455ac6a38b3276de91bde8cecc35684bb..9708de6d17a882ddd6e85000a030b2c9118b48aa 100644
--- a/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
+++ b/third_party/WebKit/Source/core/svg/graphics/SVGImage.cpp
@@ -571,8 +571,10 @@ 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);
   }
 }