[css-grid] Fix crash removing positioned grid item

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

Index: third_party/WebKit/Source/core/layout/LayoutGrid.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
index db381a810e2202fa81cdfe15b9fbeeef4d2ef18e..c9cc84b668b8efaaecd62ddec9284af6098e7748 100644
--- a/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutGrid.cpp
@@ -71,17 +71,21 @@ LayoutGrid* LayoutGrid::createAnonymous(Document* document) {
 void LayoutGrid::addChild(LayoutObject* newChild, LayoutObject* beforeChild) {
   LayoutBlock::addChild(newChild, beforeChild);
 
-  // The grid needs to be recomputed as it might contain auto-placed items that
-  // will change their position.
-  dirtyGrid();
+  if (!newChild->isOutOfFlowPositioned()) {

[jfernandez, 2017/03/15 09:26:36]

I think it'd be useful to add comment explaining why we don't need to mark the
grid as dirty in this case.

[Manuel Rego, 2017/03/15 10:59:26]

Done.

+    // The grid needs to be recomputed as it might contain auto-placed items
+    // that will change their position.
+    dirtyGrid();
+  }

[svillar, 2017/03/15 10:03:54]

Better to early return

if (newChild->isOutOfFlowPositioned)
   return;

[Manuel Rego, 2017/03/15 10:59:26]

Acknowledged.

 }
 
 void LayoutGrid::removeChild(LayoutObject* child) {
   LayoutBlock::removeChild(child);
 
-  // The grid needs to be recomputed as it might contain auto-placed items that
-  // will change their position.
-  dirtyGrid();
+  if (!child->isOutOfFlowPositioned()) {
+    // The grid needs to be recomputed as it might contain auto-placed items
+    // that will change their position.
+    dirtyGrid();
+  }

[svillar, 2017/03/15 10:03:54]

Ditto.

[Manuel Rego, 2017/03/15 10:59:26]

Acknowledged.

 }
 
 void LayoutGrid::styleDidChange(StyleDifference diff,