Float layer should ignore offsets from ancestor inline layers under containing block

third_party/WebKit/Source/core/paint/PaintLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 764 matching lines @@
     IntRect lineBox = enclosingIntRect(inlineFlow->linesBoundingBox());
     m_size = lineBox.size();
   } else if (LayoutBox* box = layoutBox()) {
     IntSize newSize = pixelSnappedIntSize(box->size(), box->location());
     didResize = newSize != m_size;
     m_size = newSize;
     localPoint.moveBy(box->physicalLocation());
   }
 
   if (!layoutObject()->isOutOfFlowPositioned() &&
-      !layoutObject()->isColumnSpanAll() && layoutObject()->parent()) {
+      !layoutObject()->isColumnSpanAll()) {
     // We must adjust our position by walking up the layout tree looking for the
     // nearest enclosing object with a layer.
-    LayoutObject* curr = layoutObject()->parent();
+    LayoutObject* curr = layoutObject()->container();
     while (curr && !curr->hasLayer()) {
       if (curr->isBox() && !curr->isTableRow()) {
         // Rows and cells share the same coordinate space (that of the section).
         // Omit them when computing our xpos/ypos.
         localPoint.moveBy(toLayoutBox(curr)->physicalLocation());
       }
-      curr = curr->parent();
+      curr = curr->container();
     }
-    if (curr->isBox() && curr->isTableRow()) {
+    if (curr && curr->isTableRow()) {
       // Put ourselves into the row coordinate space.
       localPoint.moveBy(-toLayoutBox(curr)->physicalLocation());
     }
   }
 
   // Subtract our parent's scroll offset.
   if (PaintLayer* containingLayer =
           layoutObject()->isOutOfFlowPositioned()
               ? containingLayerForOutOfFlowPositioned()
               : nullptr) {
@@ skipping 603 matching lines @@
 
   if (position == FixedPosition &&
       (!ancestorLayer || ancestorLayer == layoutObject->view()->layer())) {
     // If the fixed layer's container is the root, just add in the offset of the
     // view. We can obtain this by calling localToAbsolute() on the LayoutView.
     FloatPoint absPos = layoutObject->localToAbsolute();
     location += LayoutSize(absPos.x(), absPos.y());
     return ancestorLayer;
   }
 
-  PaintLayer* parentLayer;
-  if (position == AbsolutePosition || position == FixedPosition) {
-    bool foundAncestorFirst;
-    parentLayer = layer->containingLayerForOutOfFlowPositioned(
-        ancestorLayer, &foundAncestorFirst);
+  PaintLayer* parentLayer = nullptr;
+  if (position == AbsolutePosition || position == FixedPosition ||
+      (layoutObject->isFloating() && layoutObject->parent() &&
+       !layoutObject->parent()->isLayoutBlockFlow())) {
+    bool foundAncestorFirst = false;
+    if (layoutObject->isFloating()) {
+      Optional<LayoutObject::AncestorSkipInfo> skipInfo;
+      if (ancestorLayer)
+        skipInfo.emplace(ancestorLayer->layoutObject());
+      if (auto* containingBlock = layoutObject->containingBlock(
+              ancestorLayer ? &*skipInfo : nullptr)) {
+        parentLayer = containingBlock->enclosingLayer();
+        foundAncestorFirst = ancestorLayer && skipInfo->ancestorSkipped();
+      }
+    } else {
+      parentLayer = layer->containingLayerForOutOfFlowPositioned(
+          ancestorLayer, &foundAncestorFirst);
+    }
 
     if (foundAncestorFirst) {
       // Found ancestorLayer before the container of the out-of-flow object, so
       // compute offset of both relative to the container and subtract.
 
       LayoutPoint thisCoords;
       layer->convertToLayerCoords(parentLayer, thisCoords);
 
       LayoutPoint ancestorCoords;
       ancestorLayer->convertToLayerCoords(parentLayer, ancestorCoords);
@@ skipping 1785 matching lines @@
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject) {
   if (!layoutObject) {
     LOG(INFO) << "Cannot showLayerTree. Root is (nil)";
     return;
   }
   showLayerTree(layoutObject->enclosingLayer());
 }
 #endif