[cleanup] Use ClearLayoutResults in LayoutBox::UpdateAfterLayout()

Followup from:
https://chromium-review.googlesource.com/c/chromium/src/+/2031547

Change-Id: I06de15554a90534978ef11c0516e81742058b834
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2035860
Commit-Queue: Koji Ishii <kojii@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Cr-Commit-Position: refs/heads/master@{#738054}

third_party/blink/renderer/core/layout/layout_box.cc

@@ -779,10 +779,8 @@ void LayoutBox::UpdateAfterLayout() {
   // We also want to make sure that if our entrance point into layout changes,
   // e.g. an OOF-positioned object is laid out by an NG containing block, then
   // Legacy, then NG again, NG won't use a stale layout result.
-  if (IsOutOfFlowPositioned() && !IsLayoutNGObject()) {
-    measure_result_.reset();
-    layout_results_.clear();
-  }
+  if (IsOutOfFlowPositioned() && !IsLayoutNGObject())
+    ClearLayoutResults();
 }
 
 bool LayoutBox::HasOverrideIntrinsicContentWidth() const {