Bug 1684214 - Change GetComputedStyleNoFlush to take a const element parameter r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D100463

layout/style/ServoStyleSet.cpp

@@ -1098,7 +1098,7 @@ void ServoStyleSet::ClearNonInheritingComputedStyles() {
 }
 
 already_AddRefed<ComputedStyle> ServoStyleSet::ResolveStyleLazily(
-    Element& aElement, PseudoStyleType aPseudoType,
+    const Element& aElement, PseudoStyleType aPseudoType,
     StyleRuleInclusion aRuleInclusion) {
   PreTraverseSync();
   MOZ_ASSERT(GetPresContext(),
@@ -1118,7 +1118,7 @@ already_AddRefed<ComputedStyle> ServoStyleSet::ResolveStyleLazily(
    * getComputedStyle, the only API where this can be observed, to look at the
    * style of the pseudo-element if it exists instead.
    */
-  Element* elementForStyleResolution = &aElement;
+  const Element* elementForStyleResolution = &aElement;
   PseudoStyleType pseudoTypeForStyleResolution = aPseudoType;
   if (aPseudoType == PseudoStyleType::before) {
     if (Element* pseudo = nsLayoutUtils::GetBeforePseudo(&aElement)) {

layout/style/ServoStyleSet.h

@@ -210,10 +210,8 @@ class ServoStyleSet {
   // style has been resolved. If the element was unstyled and a new style
   // was resolved, it is not stored in the DOM. (That is, the element remains
   // unstyled.)
-  //
-  // TODO(emilio): Element argument should be `const`.
   already_AddRefed<ComputedStyle> ResolveStyleLazily(
-      dom::Element&, PseudoStyleType = PseudoStyleType::NotPseudo,
+      const dom::Element&, PseudoStyleType = PseudoStyleType::NotPseudo,
       StyleRuleInclusion = StyleRuleInclusion::All);
 
   // Get a ComputedStyle for an anonymous box. The pseudo type must be an

layout/style/nsComputedDOMStyle.cpp

@@ -84,7 +84,8 @@ static nsDOMCSSValueList* GetROCSSValueList(bool aCommaDelimited) {
   return new nsDOMCSSValueList(aCommaDelimited);
 }
 
-static Element* GetRenderedElement(Element* aElement, nsAtom* aPseudo) {
+static const Element* GetRenderedElement(const Element* aElement,
+                                         nsAtom* aPseudo) {
   if (aPseudo == nsCSSPseudoElements::before()) {
     return nsLayoutUtils::GetBeforePseudo(aElement);
   }
@@ -170,7 +171,7 @@ static bool ElementNeedsRestyle(Element* aElement, nsAtom* aPseudo,
 
   // If there's a pseudo, we need to prefer that element, as the pseudo itself
   // may have explicit restyles.
-  Element* styledElement = GetRenderedElement(aElement, aPseudo);
+  const Element* styledElement = GetRenderedElement(aElement, aPseudo);
   // Try to skip the restyle otherwise.
   return Servo_HasPendingRestyleAncestor(
       styledElement ? styledElement : aElement, aMayNeedToFlushLayout);
@@ -497,7 +498,7 @@ static inline PseudoStyleType GetPseudoType(nsAtom* aPseudo) {
 }
 
 already_AddRefed<ComputedStyle> nsComputedDOMStyle::DoGetComputedStyleNoFlush(
-    Element* aElement, nsAtom* aPseudo, PresShell* aPresShell,
+    const Element* aElement, nsAtom* aPseudo, PresShell* aPresShell,
     StyleType aStyleType) {
   MOZ_ASSERT(aElement, "NULL element");
 
@@ -535,7 +536,7 @@ already_AddRefed<ComputedStyle> nsComputedDOMStyle::DoGetComputedStyleNoFlush(
   // mPrimaryFrame). Remove it once that's fixed.
   if (inDocWithShell && aStyleType == eAll &&
       !aElement->IsHTMLElement(nsGkAtoms::area)) {
-    if (Element* element = GetRenderedElement(aElement, aPseudo)) {
+    if (const Element* element = GetRenderedElement(aElement, aPseudo)) {
       if (nsIFrame* styleFrame = nsLayoutUtils::GetStyleFrame(element)) {
         ComputedStyle* result = styleFrame->Style();
         // Don't use the style if it was influenced by pseudo-elements,

layout/style/nsComputedDOMStyle.h

@@ -92,7 +92,7 @@ class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
       Element* aElement, nsAtom* aPseudo, StyleType aStyleType = eAll);
 
   static already_AddRefed<ComputedStyle> GetComputedStyleNoFlush(
-      Element* aElement, nsAtom* aPseudo, StyleType aStyleType = eAll) {
+      const Element* aElement, nsAtom* aPseudo, StyleType aStyleType = eAll) {
     return DoGetComputedStyleNoFlush(
         aElement, aPseudo, nsContentUtils::GetPresShellForContent(aElement),
         aStyleType);
@@ -158,7 +158,7 @@ class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
   void SetFrameComputedStyle(ComputedStyle* aStyle, uint64_t aGeneration);
 
   static already_AddRefed<ComputedStyle> DoGetComputedStyleNoFlush(
-      Element* aElement, nsAtom* aPseudo, mozilla::PresShell* aPresShell,
+      const Element* aElement, nsAtom* aPseudo, mozilla::PresShell* aPresShell,
       StyleType aStyleType);
 
 #define STYLE_STRUCT(name_)                \