Don't force layout for scrollTo(0,0).

Source/core/frame/LocalDOMWindow.cpp

Index: Source/core/frame/LocalDOMWindow.cpp
diff --git a/Source/core/frame/LocalDOMWindow.cpp b/Source/core/frame/LocalDOMWindow.cpp
index 0c636c0bd315c613ab58748e3a472d3563458a3d..2b4002e5bd41cb79b7d8d80a3b90a3b75f179829 100644
--- a/Source/core/frame/LocalDOMWindow.cpp
+++ b/Source/core/frame/LocalDOMWindow.cpp
@@ -1210,11 +1210,14 @@ void LocalDOMWindow::scrollTo(double x, double y) const
     if (!isCurrentlyDisplayedInFrame())
         return;
 
-    document()->updateLayoutIgnorePendingStylesheets();
-
     if (std::isnan(x) || std::isnan(y))
         return;
 
+    // It is only necessary to have an up-to-date layout if the position may be clamped,
+    // which is never the case for (0, 0).
+    if (x || y)
+        document()->updateLayoutIgnorePendingStylesheets();
+
     DoublePoint layoutPos(x * frame()->pageZoomFactor(), y * frame()->pageZoomFactor());
     scrollViewportTo(frame(), layoutPos, ScrollBehaviorAuto);
 }
@@ -1224,8 +1227,6 @@ void LocalDOMWindow::scrollTo(const ScrollToOptions& scrollToOptions) const
     if (!isCurrentlyDisplayedInFrame())
         return;
 
-    document()->updateLayoutIgnorePendingStylesheets();
-
     FrameView* view = frame()->view();
     if (!view)
         return;
@@ -1234,6 +1235,15 @@ void LocalDOMWindow::scrollTo(const ScrollToOptions& scrollToOptions) const
     if (!host)
         return;
 
+    // It is only necessary to have an up-to-date layout if the position may be clamped,
+    // which is never the case for (0, 0).
+    if (!scrollToOptions.hasLeft()
+        || !scrollToOptions.hasTop()
+        || scrollToOptions.left()
+        || scrollToOptions.top()) {
+        document()->updateLayoutIgnorePendingStylesheets();
+    }
+
     double scaledX = 0.0;
     double scaledY = 0.0;