Call getUncachedPseudoStyle on correct node for ::selection.

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 1366 matching lines @@
 bool LayoutObject::isSelectable() const {
   return !isInert() &&
          !(style()->userSelect() == SELECT_NONE &&
            style()->userModify() == READ_ONLY);
 }
 
 Color LayoutObject::selectionBackgroundColor() const {
   if (!isSelectable())
     return Color::transparent;
 
-  if (RefPtr<ComputedStyle> pseudoStyle =
-          getUncachedPseudoStyleFromParentOrShadowHost())
+  if (RefPtr<ComputedStyle> pseudoStyle = getUncachedSelectionStyle())
     return resolveColor(*pseudoStyle, CSSPropertyBackgroundColor)
         .blendWithWhite();
   return frame()->selection().isFocusedAndActive()
              ? LayoutTheme::theme().activeSelectionBackgroundColor()
              : LayoutTheme::theme().inactiveSelectionBackgroundColor();
 }
 
 Color LayoutObject::selectionColor(
     int colorProperty,
     const GlobalPaintFlags globalPaintFlags) const {
   // If the element is unselectable, or we are only painting the selection,
   // don't override the foreground color with the selection foreground color.
   if (!isSelectable() || (globalPaintFlags & GlobalPaintSelectionOnly))
     return resolveColor(colorProperty);
 
-  if (RefPtr<ComputedStyle> pseudoStyle =
-          getUncachedPseudoStyleFromParentOrShadowHost())
+  if (RefPtr<ComputedStyle> pseudoStyle = getUncachedSelectionStyle())
     return resolveColor(*pseudoStyle, colorProperty);
   if (!LayoutTheme::theme().supportsSelectionForegroundColors())
     return resolveColor(colorProperty);
   return frame()->selection().isFocusedAndActive()
              ? LayoutTheme::theme().activeSelectionForegroundColor()
              : LayoutTheme::theme().inactiveSelectionForegroundColor();
 }
 
 Color LayoutObject::selectionForegroundColor(
     const GlobalPaintFlags globalPaintFlags) const {
@@ skipping 1644 matching lines @@
         document().ensureStyleResolver().styleForElement(
             element, parentStyle, parentStyle, DisallowStyleSharing);
     result->setStyleType(PseudoIdFirstLineInherited);
     return result.release();
   }
 
   return document().ensureStyleResolver().pseudoStyleForElement(
       element, pseudoStyleRequest, parentStyle, parentStyle);
 }
 
-PassRefPtr<ComputedStyle>
-LayoutObject::getUncachedPseudoStyleFromParentOrShadowHost() const {
+PassRefPtr<ComputedStyle> LayoutObject::getUncachedSelectionStyle() const {
   if (!node())
     return nullptr;
 
+  // In Blink, ::selection only applies to direct children of the element on
+  // which ::selection is matched. In order to be able to style ::selection
+  // inside elements implemented with a UA shadow tree, like input::selection,
+  // we calculate ::selection style on the shadow host for elements inside the
+  // UA shadow.
   if (ShadowRoot* root = node()->containingShadowRoot()) {
     if (root->type() == ShadowRootType::UserAgent) {
       if (Element* shadowHost = node()->ownerShadowHost()) {
         return shadowHost->layoutObject()->getUncachedPseudoStyle(
             PseudoStyleRequest(PseudoIdSelection));
       }
     }
   }
 
-  return getUncachedPseudoStyle(PseudoStyleRequest(PseudoIdSelection));
+  // If we request ::selection style for LayoutText, query ::selection style on
+  // the parent element instead, as that is the node for which ::selection
+  // matches.
+  const LayoutObject* selectionLayoutObject = this;
+  Element* element = Traversal<Element>::firstAncestorOrSelf(*node());
+  if (!element)
+    return nullptr;
+  if (element != node()) {
+    selectionLayoutObject = element->layoutObject();
+    if (!selectionLayoutObject)
+      return nullptr;
+  }
+  return selectionLayoutObject->getUncachedPseudoStyle(
+      PseudoStyleRequest(PseudoIdSelection));
 }
 
 void LayoutObject::addAnnotatedRegions(Vector<AnnotatedRegionValue>& regions) {
   // Convert the style regions to absolute coordinates.
   if (style()->visibility() != EVisibility::kVisible || !isBox())
     return;
 
   if (style()->getDraggableRegionMode() == DraggableRegionNone)
     return;
 
@@ skipping 436 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