Bug 1494321 p2. Stop doing wasteful pre/post-effects work for frames with just a clip-path or mask applied. r=miko

Differential Revision: https://phabricator.services.mozilla.com/D6924

--HG--
extra : rebase_source : 426e4b6d854644db1524d235651667e23d9c4908

layout/generic/nsFrame.cpp

@@ -7346,7 +7346,7 @@ ComputeEffectsRect(nsIFrame* aFrame, const nsRect& aOverflowRect,
   // only one heap-allocated rect per frame and it will be cleaned up when
   // the frame dies.
 
-  if (nsSVGIntegrationUtils::UsingEffectsForFrame(aFrame)) {
+  if (nsSVGIntegrationUtils::UsingOverflowAffectingEffects(aFrame)) {
     aFrame->SetProperty
       (nsIFrame::PreEffectsBBoxProperty(), new nsRect(r));
     r = nsSVGIntegrationUtils::ComputePostEffectsVisualOverflowRect(aFrame, r);

layout/style/nsStyleStruct.cpp

@@ -1287,9 +1287,6 @@ nsStyleSVGReset::CalcDifference(const nsStyleSVGReset& aNewData) const
   if (mClipPath != aNewData.mClipPath) {
     hint |= nsChangeHint_UpdateEffects |
             nsChangeHint_RepaintFrame;
-    // clip-path changes require that we update the PreEffectsBBoxProperty,
-    // which is done during overflow computation.
-    hint |= nsChangeHint_UpdateOverflow;
   }
 
   if (mDominantBaseline != aNewData.mDominantBaseline) {
@@ -3246,14 +3243,6 @@ nsStyleImageLayers::Layer::CalcDifference(const nsStyleImageLayers::Layer& aNewL
     if (!maybeSVGMask && aNewLayer.mImage.GetURLValue()) {
       maybeSVGMask = aNewLayer.mImage.GetURLValue()->MightHaveRef();
     }
-
-    // Return nsChangeHint_UpdateOverflow if either URI might link to an SVG
-    // mask.
-    if (maybeSVGMask) {
-      // Mask changes require that we update the PreEffectsBBoxProperty,
-      // which is done during overflow computation.
-      hint |= nsChangeHint_UpdateOverflow;
-    }
   } else if (mAttachment != aNewLayer.mAttachment ||
              mClip != aNewLayer.mClip ||
              mOrigin != aNewLayer.mOrigin ||

layout/svg/nsSVGIntegrationUtils.cpp

@@ -96,7 +96,8 @@ private:
     // This function may be called during reflow or painting. We should only
     // do this check in painting process since the PreEffectsBBoxProperty of
     // continuations are not set correctly while reflowing.
-    if (nsSVGIntegrationUtils::UsingEffectsForFrame(aFrame) && !aInReflow) {
+    if (nsSVGIntegrationUtils::UsingOverflowAffectingEffects(aFrame) &&
+        !aInReflow) {
       nsOverflowAreas* preTransformOverflows =
         aFrame->GetProperty(aFrame->PreTransformOverflowAreasProperty());
 
@@ -157,6 +158,14 @@ GetPreEffectsVisualOverflow(nsIFrame* aFirstContinuation,
   return collector.GetResult() + aFirstContinuationToUserSpace;
 }
 
+bool
+nsSVGIntegrationUtils::UsingOverflowAffectingEffects(const nsIFrame* aFrame)
+{
+  // Currently overflow don't take account of SVG or other non-absolute
+  // positioned clipping, or masking.
+  return aFrame->StyleEffects()->HasFilters();
+}
+
 bool
 nsSVGIntegrationUtils::UsingEffectsForFrame(const nsIFrame* aFrame)
 {

layout/svg/nsSVGIntegrationUtils.h

@@ -44,6 +44,13 @@ class nsSVGIntegrationUtils final
   typedef mozilla::image::imgDrawingParams imgDrawingParams;
 
 public:
+  /**
+   * Returns true if SVG effects that affect the overflow of the given frame
+   * are currently applied to the frame.
+   */
+  static bool
+  UsingOverflowAffectingEffects(const nsIFrame* aFrame);
+
   /**
    * Returns true if SVG effects are currently applied to this frame.
    */