Modify v1-distribution PerformanceTest

third_party/WebKit/PerformanceTests/ShadowDOM/v1-distribution.html

Index: third_party/WebKit/PerformanceTests/ShadowDOM/v1-distribution.html
diff --git a/third_party/WebKit/PerformanceTests/ShadowDOM/v1-distribution.html b/third_party/WebKit/PerformanceTests/ShadowDOM/v1-distribution.html
index 98bd3c68a51277ff0c85d53f0c75f046054fe4a5..a3d9d6248a3474360f46c43da72dc288d9bb9c3b 100644
--- a/third_party/WebKit/PerformanceTests/ShadowDOM/v1-distribution.html
+++ b/third_party/WebKit/PerformanceTests/ShadowDOM/v1-distribution.html
@@ -28,9 +28,9 @@ function run() {
   let div = document.createElement('div');
   for (let i = 0; i < loops; ++i) {
     host.appendChild(div);
-    slot.getDistributedNodes();;
+    slot.getAssignedNodes({flatten: true});
     host.removeChild(div);
-    slot.getDistributedNodes();;
+    slot.getAssignedNodes({flatten: true});
   }
 }