Bug 1896711 part 2: Use MakeRefPtr to reduce boilerplate, in layout/svg. r=TYLin

Also remove one unnecessary null-check for an object that we're allocating
infallibly.

Differential Revision: https://phabricator.services.mozilla.com/D210388

layout/svg/SVGMarkerFrame.cpp

@@ -134,7 +134,7 @@ void SVGMarkerFrame::PaintMark(gfxContext& aContext,
   ISVGDisplayableFrame* SVGFrame = do_QueryFrame(kid);
   // The CTM of each frame referencing us may be different.
   SVGFrame->NotifySVGChanged(ISVGDisplayableFrame::TRANSFORM_CHANGED);
-  RefPtr<SVGContextPaintImpl> contextPaint = new SVGContextPaintImpl();
+  auto contextPaint = MakeRefPtr<SVGContextPaintImpl>();
   contextPaint->Init(aContext.GetDrawTarget(), aContext.CurrentMatrixDouble(),
                      aMarkedFrame, SVGContextPaint::GetContextPaint(marker),
                      aImgParams);

layout/svg/SVGObserverUtils.cpp

@@ -1676,8 +1676,7 @@ Element* SVGObserverUtils::GetAndObserveBackgroundImage(nsIFrame* aFrame,
       aFrame->GetContent()
           ->OwnerDoc()
           ->ReferrerInfoForInternalCSSAndSVGResources();
-  RefPtr<URLAndReferrerInfo> url =
-      new URLAndReferrerInfo(targetURI, referrerInfo);
+  auto url = MakeRefPtr<URLAndReferrerInfo>(targetURI, referrerInfo);
 
   return static_cast<SVGMozElementObserver*>(
              hashtable

layout/svg/SVGPatternFrame.cpp

@@ -688,13 +688,9 @@ already_AddRefed<gfxPattern> SVGPatternFrame::GetPaintServerPattern(
     return nullptr;
   }
 
-  RefPtr<gfxPattern> pattern = new gfxPattern(surface, pMatrix);
-
-  if (!pattern) {
-    return nullptr;
-  }
-
+  auto pattern = MakeRefPtr<gfxPattern>(surface, pMatrix);
   pattern->SetExtend(ExtendMode::REPEAT);
+
   return pattern.forget();
 }
 

layout/svg/SVGTextFrame.cpp

@@ -3142,7 +3142,7 @@ void SVGTextFrame::PaintSVG(gfxContext& aContext, const gfxMatrix& aTransform,
   while (run.mFrame) {
     nsTextFrame* frame = run.mFrame;
 
-    RefPtr<SVGContextPaintImpl> contextPaint = new SVGContextPaintImpl();
+    auto contextPaint = MakeRefPtr<SVGContextPaintImpl>();
     DrawMode drawMode = contextPaint->Init(&aDrawTarget, initialMatrix, frame,
                                            outerContextPaint, aImgParams);
     if (drawMode & DrawMode::GLYPH_STROKE) {

layout/svg/SVGUtils.cpp

@@ -513,7 +513,7 @@ class MixModeBlender {
 
     gfxContextAutoSaveRestore save(mSourceCtx);
     mSourceCtx->SetMatrix(Matrix());  // This will be restored right after.
-    RefPtr<gfxPattern> pattern = new gfxPattern(
+    auto pattern = MakeRefPtr<gfxPattern>(
         targetSurf, Matrix::Translation(mTargetOffset.x, mTargetOffset.y));
     mSourceCtx->SetPattern(pattern);
     mSourceCtx->Paint();