[Squad] Move parts of CanGeneratePseudoElement to ComputedStyle.

Bug: 836126
Change-Id: Ifd1705c3d72af1c9250f97279a03f439ee08d478
Reviewed-on: https://chromium-review.googlesource.com/1109824
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Anders Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569250}

third_party/blink/renderer/core/css/resolver/style_resolver.cc

@@ -809,21 +809,14 @@ PseudoElement* StyleResolver::CreatePseudoElementIfNeeded(Element& parent,
   if (!parent.CanGeneratePseudoElement(pseudo_id))
     return nullptr;
 
-  ComputedStyle* parent_style = parent.MutableComputedStyle();
-  DCHECK(parent_style);
-
-  // The first letter pseudo element has to look up the tree and see if any
-  // of the ancestors are first letter.
-  if (pseudo_id < kFirstInternalPseudoId && pseudo_id != kPseudoIdFirstLetter &&
-      !parent_style->HasPseudoStyle(pseudo_id)) {
-    return nullptr;
-  }
-
   if (pseudo_id == kPseudoIdFirstLetter &&
       (parent.IsSVGElement() ||
        !FirstLetterPseudoElement::FirstLetterTextLayoutObject(parent)))
     return nullptr;
 
+  ComputedStyle* parent_style = parent.MutableComputedStyle();
+  DCHECK(parent_style);
+
   if (ComputedStyle* cached_style =
           parent_style->GetCachedPseudoStyle(pseudo_id)) {
     if (!PseudoElementLayoutObjectIsNeeded(cached_style))

third_party/blink/renderer/core/dom/element.cc

@@ -3994,17 +3994,8 @@ scoped_refptr<ComputedStyle> Element::GetUncachedPseudoStyle(
 bool Element::CanGeneratePseudoElement(PseudoId pseudo_id) const {
   if (pseudo_id == kPseudoIdBackdrop && !IsInTopLayer())
     return false;
-  if (const ComputedStyle* style = GetComputedStyle()) {
-    if (style->Display() == EDisplay::kNone)
-      return false;
-    if (style->Display() == EDisplay::kContents) {
-      // For display: contents elements, we still need to generate ::before and
-      // ::after, but the rest of the pseudo-elements should only be used for
-      // elements with an actual layout object.
-      return pseudo_id == kPseudoIdBefore || pseudo_id == kPseudoIdAfter;
-    }
-    return true;
-  }
+  if (const ComputedStyle* style = GetComputedStyle())
+    return style->CanGeneratePseudoElement(pseudo_id);
   return false;
 }
 

third_party/blink/renderer/core/style/computed_style.h

@@ -2218,6 +2218,21 @@ class ComputedStyle : public ComputedStyleBase,
 
   InterpolationQuality GetInterpolationQuality() const;
 
+  bool CanGeneratePseudoElement(PseudoId pseudo) const {
+    // The first letter pseudo element has to look up the tree and see if any
+    // of the ancestors are first letter.
+    if (pseudo != kPseudoIdFirstLetter && !HasPseudoStyle(pseudo))
+      return false;
+    if (Display() == EDisplay::kNone)
+      return false;
+    if (Display() != EDisplay::kContents)
+      return true;
+    // For display: contents elements, we still need to generate ::before and
+    // ::after, but the rest of the pseudo-elements should only be used for
+    // elements with an actual layout object.
+    return pseudo == kPseudoIdBefore || pseudo == kPseudoIdAfter;
+  }
+
  private:
   void SetVisitedLinkBackgroundColor(const StyleColor& v) {
     SetVisitedLinkBackgroundColorInternal(v);