Bug 1774879 part 4: Use const ComputedStyle* arg in nsCSSRendering::PaintStyleImageLayerWithSC, and update several callsites now that they can pass const variables. r=emilio

This patch doesn't change behavior; it's just a const-correctness fix.

Thanks to previous patches in this series, PaintStyleImageLayerWithSC's arg can
become const, so let's make that change and opportunistically make the same
change to the variables that callers pass in, where possible.

Differential Revision: https://phabricator.services.mozilla.com/D149677

layout/painting/nsCSSRendering.cpp

@@ -1796,7 +1796,7 @@ ImgDrawResult nsCSSRendering::PaintStyleImageLayer(const PaintBGParams& aParams,
   MOZ_ASSERT(aParams.frame,
              "Frame is expected to be provided to PaintStyleImageLayer");
 
-  ComputedStyle* sc = FindBackground(aParams.frame);
+  const ComputedStyle* sc = FindBackground(aParams.frame);
   if (!sc) {
     // We don't want to bail out if moz-appearance is set on a root
     // node. If it has a parent content node, bail because it's not
@@ -2387,7 +2387,7 @@ static CompositionOp DetermineCompositionOp(
 
 ImgDrawResult nsCSSRendering::PaintStyleImageLayerWithSC(
     const PaintBGParams& aParams, gfxContext& aRenderingCtx,
-    ComputedStyle* aBackgroundSC, const nsStyleBorder& aBorder) {
+    const ComputedStyle* aBackgroundSC, const nsStyleBorder& aBorder) {
   MOZ_ASSERT(aParams.frame,
              "Frame is expected to be provided to PaintStyleImageLayerWithSC");
 

layout/painting/nsCSSRendering.h

@@ -503,7 +503,8 @@ struct nsCSSRendering {
    */
   static ImgDrawResult PaintStyleImageLayerWithSC(
       const PaintBGParams& aParams, gfxContext& aRenderingCtx,
-      mozilla::ComputedStyle* mBackgroundSC, const nsStyleBorder& aBorder);
+      const mozilla::ComputedStyle* aBackgroundSC,
+      const nsStyleBorder& aBorder);
 
   static bool CanBuildWebRenderDisplayItemsForStyleImageLayer(
       WebRenderLayerManager* aManager, nsPresContext& aPresCtx,

layout/svg/SVGIntegrationUtils.cpp

@@ -491,7 +491,7 @@ using PaintFramesParams = SVGIntegrationUtils::PaintFramesParams;
  */
 static bool PaintMaskSurface(const PaintFramesParams& aParams,
                              DrawTarget* aMaskDT, float aOpacity,
-                             ComputedStyle* aSC,
+                             const ComputedStyle* aSC,
                              const nsTArray<SVGMaskFrame*>& aMaskFrames,
                              const nsPoint& aOffsetToUserSpace) {
   MOZ_ASSERT(aMaskFrames.Length() > 0);
@@ -568,7 +568,7 @@ struct MaskPaintResult {
 };
 
 static MaskPaintResult CreateAndPaintMaskSurface(
-    const PaintFramesParams& aParams, float aOpacity, ComputedStyle* aSC,
+    const PaintFramesParams& aParams, float aOpacity, const ComputedStyle* aSC,
     const nsTArray<SVGMaskFrame*>& aMaskFrames,
     const nsPoint& aOffsetToUserSpace) {
   const nsStyleSVGReset* svgReset = aSC->StyleSVGReset();