Get rid of ownStyle in LayoutObject::getUncachedPseudoStyle.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  *               (http://www.torchmobile.com/)
@@ skipping 1941 matching lines @@
   if (oldStyle.hasPseudoStyle(PseudoIdSelection) ||
       styleRef().hasPseudoStyle(PseudoIdSelection))
     invalidatePaintForSelection();
 }
 
 void LayoutObject::applyFirstLineChanges(const ComputedStyle& oldStyle) {
   if (oldStyle.hasPseudoStyle(PseudoIdFirstLine)) {
     RefPtr<ComputedStyle> oldPseudoStyle =
         oldStyle.getCachedPseudoStyle(PseudoIdFirstLine);
     if (styleRef().hasPseudoStyle(PseudoIdFirstLine) && oldPseudoStyle) {
-      RefPtr<ComputedStyle> newPseudoStyle =
-          uncachedFirstLineStyle(mutableStyle());
+      RefPtr<ComputedStyle> newPseudoStyle = uncachedFirstLineStyle();
       if (newPseudoStyle) {
         firstLineStyleDidChange(*oldPseudoStyle, *newPseudoStyle);
         return;
       }
     }
   }
   setNeedsLayoutAndPrefWidthsRecalc(LayoutInvalidationReason::StyleChange);
 }
 
 void LayoutObject::propagateStyleToAnonymousChildren() {
@@ skipping 1050 matching lines @@
   if (layoutObject->isBeforeOrAfterContent())
     layoutObjectForFirstLineStyle = layoutObject->parent();
 
   if (layoutObjectForFirstLineStyle->behavesLikeBlockContainer()) {
     if (const LayoutBlock* firstLineBlock =
             toLayoutBlock(layoutObjectForFirstLineStyle)
                 ->enclosingFirstLineStyleBlock()) {
       if (type == Cached)
         return firstLineBlock->getCachedPseudoStyle(PseudoIdFirstLine, style);
       return firstLineBlock->getUncachedPseudoStyle(
-          PseudoStyleRequest(PseudoIdFirstLine), style,
-          firstLineBlock == layoutObject ? style : 0);
+          PseudoStyleRequest(PseudoIdFirstLine), style);
     }
   } else if (!layoutObjectForFirstLineStyle->isAnonymous() &&
              layoutObjectForFirstLineStyle->isLayoutInline() &&
              !layoutObjectForFirstLineStyle->node()
                   ->isFirstLetterPseudoElement()) {
     const ComputedStyle* parentStyle =
         layoutObjectForFirstLineStyle->parent()->firstLineStyle();
     if (parentStyle != layoutObjectForFirstLineStyle->parent()->style()) {
       if (type == Cached) {
         // A first-line style is in effect. Cache a first-line style for
         // ourselves.
         layoutObjectForFirstLineStyle->mutableStyleRef().setHasPseudoStyle(
             PseudoIdFirstLineInherited);
         return layoutObjectForFirstLineStyle->getCachedPseudoStyle(
             PseudoIdFirstLineInherited, parentStyle);
       }
       return layoutObjectForFirstLineStyle->getUncachedPseudoStyle(
-          PseudoStyleRequest(PseudoIdFirstLineInherited), parentStyle, style);
+          PseudoStyleRequest(PseudoIdFirstLineInherited), parentStyle);
     }
   }
   return nullptr;
 }
 
-PassRefPtr<ComputedStyle> LayoutObject::uncachedFirstLineStyle(
-    ComputedStyle* style) const {
+PassRefPtr<ComputedStyle> LayoutObject::uncachedFirstLineStyle() const {
   if (!document().styleEngine().usesFirstLineRules())
     return nullptr;
 
   ASSERT(!isText());
 
-  return firstLineStyleForCachedUncachedType(Uncached, this, style);
+  return firstLineStyleForCachedUncachedType(Uncached, this, m_style.get());
 }
 
 ComputedStyle* LayoutObject::cachedFirstLineStyle() const {
   ASSERT(document().styleEngine().usesFirstLineRules());
 
   if (RefPtr<ComputedStyle> style = firstLineStyleForCachedUncachedType(
           Cached, isText() ? parent() : this, m_style.get()))
     return style.get();
 
   return m_style.get();
@@ skipping 11 matching lines @@
 
   RefPtr<ComputedStyle> result =
       getUncachedPseudoStyle(PseudoStyleRequest(pseudo), parentStyle);
   if (result)
     return mutableStyleRef().addCachedPseudoStyle(result.release());
   return nullptr;
 }
 
 PassRefPtr<ComputedStyle> LayoutObject::getUncachedPseudoStyle(
     const PseudoStyleRequest& pseudoStyleRequest,
-    const ComputedStyle* parentStyle,
-    const ComputedStyle* ownStyle) const {
-  if (pseudoStyleRequest.pseudoId < FirstInternalPseudoId && !ownStyle &&
+    const ComputedStyle* parentStyle) const {
+  if (pseudoStyleRequest.pseudoId < FirstInternalPseudoId &&
       !style()->hasPseudoStyle(pseudoStyleRequest.pseudoId))

[rune, 2017/03/23 22:57:46]

I'm not sure I understand this code, but it looks like we pass in ownStyle for
::first-line only, and that we always early out here for other pseudos based on
ownStyle telling us this is not ::first-line and the fact that hasPseudoStyle
needs to return true for us to have a pseudo element.

What I'm wondering is if we by removing !ownStyle early out incorrectly if
hasPseudoStyle() is false, but we still need to create a pseudo style.

Can you explain why the !ownStyle was there and why removing it won't change the
behavior?

     return nullptr;
 
-  if (!parentStyle) {
-    ASSERT(!ownStyle);
+  if (!parentStyle)
     parentStyle = style();
-  }
 
   if (!node())
     return nullptr;
 
   Element* element = Traversal<Element>::firstAncestorOrSelf(*node());
   if (!element)
     return nullptr;
 
   if (pseudoStyleRequest.pseudoId == PseudoIdFirstLineInherited) {
     RefPtr<ComputedStyle> result =
@@ skipping 527 matching lines @@
     const blink::LayoutObject* root = object1;
     while (root->parent())
       root = root->parent();
     root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
   } else {
     WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
   }
 }
 
 #endif