Don't clamp scroll positions until the end of all layouts

third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp

Index: third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp b/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp
index 994c3a841ac2a9dd41442d2b243e4f41e50156b1..7c43f5024cf49a0a7038fca7ce12044eaf5021d3 100644
--- a/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutFlexibleBox.cpp
@@ -288,8 +288,13 @@ void LayoutFlexibleBox::layoutBlock(bool relayoutChildren)
 
         layoutFlexItems(relayoutChildren, layoutScope);
 
-        if (LayoutBlock::finishDelayUpdateScrollInfo(&layoutScope))
+        ScrollPositionMap scrollMap;
+        if (LayoutBlock::finishDelayUpdateScrollInfo(&layoutScope, &scrollMap)) {
             layoutFlexItems(false, layoutScope);
+            for (auto& entry : scrollMap) {
+                entry.key->scrollToPosition(entry.value);
+            }
+        }
 
         if (logicalHeight() != previousHeight)
             relayoutChildren = true;