Call Element::rebuildLayoutTree from Document::updateStyle directly

third_party/WebKit/Source/core/dom/Element.cpp

Index: third_party/WebKit/Source/core/dom/Element.cpp
diff --git a/third_party/WebKit/Source/core/dom/Element.cpp b/third_party/WebKit/Source/core/dom/Element.cpp
index 2fde2c526802721659102806ad693fc66f3f70b6..b0c10948acf84246c270e1ccce4ed63c36b07b57 100644
--- a/third_party/WebKit/Source/core/dom/Element.cpp
+++ b/third_party/WebKit/Source/core/dom/Element.cpp
@@ -1884,7 +1884,6 @@ PassRefPtr<ComputedStyle> Element::originalStyleForLayoutObject() {
 void Element::recalcStyle(StyleRecalcChange change, Text* nextTextSibling) {
   DCHECK(document().inStyleRecalc());
   DCHECK(!document().lifecycle().inDetach());
-  DCHECK(!parentOrShadowHostNode()->needsStyleRecalc());
   DCHECK(inActiveDocument());
 
   if (hasCustomStyleCallbacks())
@@ -1901,16 +1900,20 @@ void Element::recalcStyle(StyleRecalcChange change, Text* nextTextSibling) {
           elementAnimations->setAnimationStyleChange(false);
       }
     }
-    if (parentComputedStyle())
+    if (parentComputedStyle()) {
       change = recalcOwnStyle(change, nextTextSibling);
-    clearNeedsStyleRecalc();
-    clearNeedsReattachLayoutTree();
+    } else {
+      // In case we don't perform recalcOwnStyle we will never clear the
+      // NeedsReattachLayoutTree flag which is set on the creation of each
+      // Node. Clear that here.
+      clearNeedsReattachLayoutTree();
+    }
   }
 
-  // If we reattached we don't need to recalc the style of our descendants
-  // anymore.
-  if ((change >= UpdatePseudoElements && change < Reattach) ||
-      childNeedsStyleRecalc()) {
+  // If we are going to reattach we don't need to recalc the style of
+  // our descendants anymore.
+  if (change < Reattach &&
+      (change >= UpdatePseudoElements || childNeedsStyleRecalc())) {
     SelectorFilterParentScope filterScope(*this);
     StyleSharingDepthScope sharingScope(*this);
 
@@ -1936,9 +1939,11 @@ void Element::recalcStyle(StyleRecalcChange change, Text* nextTextSibling) {
                         childNeedsStyleRecalc() ? Force : change);
 
     clearChildNeedsStyleRecalc();
-    clearChildNeedsReattachLayoutTree();
   }
 
+  if (!(needsReattachLayoutTree() || childNeedsReattachLayoutTree()))

[esprehn, 2017/02/13 22:19:41]

Run demorgans here

[nainar, 2017/02/14 03:42:09]

Done.

+    clearNeedsStyleRecalc();
+
   if (hasCustomStyleCallbacks())
     didRecalcStyle();
 }
@@ -1968,7 +1973,6 @@ PassRefPtr<ComputedStyle> Element::propagateInheritedProperties(
 StyleRecalcChange Element::recalcOwnStyle(StyleRecalcChange change,
                                           Text* nextTextSibling) {
   DCHECK(document().inStyleRecalc());
-  DCHECK(!parentOrShadowHostNode()->needsStyleRecalc());
   DCHECK(change >= IndependentInherit || needsStyleRecalc());
   DCHECK(parentComputedStyle());
 
@@ -1996,7 +2000,7 @@ StyleRecalcChange Element::recalcOwnStyle(StyleRecalcChange change,
     styleReattachData.nextTextSibling = nextTextSibling;
     document().addStyleReattachData(*this, styleReattachData);
     setNeedsReattachLayoutTree();
-    return rebuildLayoutTree();
+    return Reattach;
   }
 
   DCHECK(oldStyle);
@@ -2037,23 +2041,31 @@ StyleRecalcChange Element::recalcOwnStyle(StyleRecalcChange change,
   return localChange;
 }
 
-StyleRecalcChange Element::rebuildLayoutTree() {
+void Element::rebuildLayoutTree() {
   DCHECK(inActiveDocument());
+  DCHECK(parentNode());
+
   StyleReattachData styleReattachData = document().getStyleReattachData(*this);
   AttachContext reattachContext;
   reattachContext.resolvedStyle = styleReattachData.computedStyle.get();
   bool layoutObjectWillChange = needsAttach() || layoutObject();
 
-  // We are calling Element::rebuildLayoutTree() from inside
-  // Element::recalcOwnStyle where we set the NeedsReattachLayoutTree
-  // flag - so needsReattachLayoutTree() should always be true.
-  DCHECK(parentNode());

[esprehn, 2017/02/13 22:19:41]

Can we add these DCHECKs back?

[nainar, 2017/02/14 03:42:09]

They are back. They moved above.

-  DCHECK(parentNode()->childNeedsReattachLayoutTree());
-  DCHECK(needsReattachLayoutTree());
-  reattachLayoutTree(reattachContext);
-  // Since needsReattachLayoutTree() is always true we go into
-  // reattachLayoutTree() which reattaches all the descendant
-  // sub-trees. At this point no child should need reattaching.
+  if (needsReattachLayoutTree()) {
+    reattachLayoutTree(reattachContext);
+  } else if (childNeedsReattachLayoutTree()) {
+    DCHECK(!needsReattachLayoutTree());
+    SelectorFilterParentScope filterScope(*this);
+    StyleSharingDepthScope sharingScope(*this);
+    reattachPseudoElementLayoutTree(PseudoIdBefore);
+    rebuildShadowRootLayoutTree();
+    rebuildChildrenLayoutTrees();
+    reattachPseudoElementLayoutTree(PseudoIdAfter);
+    reattachPseudoElementLayoutTree(PseudoIdBackdrop);
+    reattachPseudoElementLayoutTree(PseudoIdFirstLetter);
+  }
+  DCHECK(!needsStyleRecalc());
+  DCHECK(!childNeedsStyleRecalc());
+  DCHECK(!needsReattachLayoutTree());
   DCHECK(!childNeedsReattachLayoutTree());
 
   if (layoutObjectWillChange || layoutObject()) {
@@ -2062,9 +2074,27 @@ StyleRecalcChange Element::rebuildLayoutTree() {
     // or store it.
     // The choice is between increased time and increased memory complexity.
     reattachWhitespaceSiblingsIfNeeded(styleReattachData.nextTextSibling);
-    return Reattach;
+  } else {
+    clearNeedsStyleRecalc();
+  }
+}
+
+void Element::rebuildShadowRootLayoutTree() {
+  for (ShadowRoot* root = youngestShadowRoot(); root;
+       root = root->olderShadowRoot()) {
+    if (root->needsReattachLayoutTree() || root->childNeedsReattachLayoutTree())
+      root->rebuildLayoutTree();
+  }
+}
+
+void Element::reattachPseudoElementLayoutTree(PseudoId pseudoId) {
+  if (PseudoElement* element = pseudoElement(pseudoId)) {
+    if (element->needsReattachLayoutTree() ||
+        element->childNeedsReattachLayoutTree())
+      element->rebuildLayoutTree();
+  } else {
+    createPseudoElementIfNeeded(pseudoId);
   }
-  return ReattachNoLayoutObject;
 }
 
 void Element::updateCallbackSelectors(const ComputedStyle* oldStyle,
@@ -3214,7 +3244,6 @@ void Element::cancelFocusAppearanceUpdate() {
 }
 
 void Element::updatePseudoElement(PseudoId pseudoId, StyleRecalcChange change) {
-  DCHECK(!needsStyleRecalc());
   PseudoElement* element = pseudoElement(pseudoId);
 
   if (element && (change == UpdatePseudoElements ||