Bug 1564526 - Remove CachedBorderImageData. r=tnikkel

See comments in the bug, which still stand.

This cache is barely hit, and when it is hit it causes correctness
issues, see bug 1815022 for a recent example.

Differential Revision: https://phabricator.services.mozilla.com/D171391

layout/generic/nsIFrame.cpp

@@ -1369,7 +1369,6 @@ void nsIFrame::DidSetComputedStyle(ComputedStyle* aOldComputedStyle) {
   if (oldBorderImage != newBorderImage) {
     // stop and restart the image loading/notification
     if (oldBorderImage && HasImageRequest()) {
-      RemoveProperty(CachedBorderImageDataProperty());
       loader->DisassociateRequestFromFrame(oldBorderImage, this);
     }
     if (newBorderImage) {

layout/generic/nsIFrame.h

@@ -1257,9 +1257,6 @@ class nsIFrame : public nsQueryFrame {
   NS_DECLARE_FRAME_PROPERTY_DELETABLE(PreTransformOverflowAreasProperty,
                                       mozilla::OverflowAreas)
 
-  NS_DECLARE_FRAME_PROPERTY_DELETABLE(CachedBorderImageDataProperty,
-                                      CachedBorderImageData)
-
   NS_DECLARE_FRAME_PROPERTY_DELETABLE(OverflowAreasProperty,
                                       mozilla::OverflowAreas)
 

layout/painting/nsCSSRenderingBorders.cpp

@@ -3429,8 +3429,6 @@ ImgDrawResult nsCSSBorderImageRenderer::DrawBorderImage(
   Maybe<nsSize> svgViewportSize =
       intrinsicSize.CanComputeConcreteSize() ? Nothing() : Some(mImageSize);
   bool hasIntrinsicRatio = intrinsicSize.HasRatio();
-  mImageRenderer.PurgeCacheForViewportChange(svgViewportSize,
-                                             hasIntrinsicRatio);
 
   // These helper tables recharacterize the 'slice' and 'width' margins
   // in a more convenient form: they are the x/y/width/height coords

layout/painting/nsImageRenderer.cpp

@@ -927,17 +927,7 @@ ImgDrawResult nsImageRenderer::DrawBorderImageComponent(
     // Retrieve or create the subimage we'll draw.
     nsIntRect srcRect(aSrc.x, aSrc.y, aSrc.width, aSrc.height);
     if (isRequestBacked) {
-      CachedBorderImageData* cachedData =
-          mForFrame->GetProperty(nsIFrame::CachedBorderImageDataProperty());
-      if (!cachedData) {
-        cachedData = new CachedBorderImageData();
-        mForFrame->AddProperty(nsIFrame::CachedBorderImageDataProperty(),
-                               cachedData);
-      }
-      if (!(subImage = cachedData->GetSubImage(aIndex))) {
-        subImage = ImageOps::Clip(mImageContainer, srcRect, aSVGViewportSize);
-        cachedData->SetSubImage(aIndex, subImage);
-      }
+      subImage = ImageOps::Clip(mImageContainer, srcRect, aSVGViewportSize);
     } else {
       // This path, for eStyleImageType_Element, is currently slower than it
       // needs to be because we don't cache anything. (In particular, if we have
@@ -1060,17 +1050,3 @@ bool nsImageRenderer::IsRasterImage() {
 already_AddRefed<imgIContainer> nsImageRenderer::GetImage() {
   return do_AddRef(mImageContainer);
 }
-
-void nsImageRenderer::PurgeCacheForViewportChange(
-    const Maybe<nsSize>& aSVGViewportSize, const bool aHasIntrinsicRatio) {
-  // Check if we should flush the cached data - only vector images need to do
-  // the check since they might not have fixed ratio.
-  if (mImageContainer &&
-      mImageContainer->GetType() == imgIContainer::TYPE_VECTOR) {
-    if (auto* cachedData =
-            mForFrame->GetProperty(nsIFrame::CachedBorderImageDataProperty())) {
-      cachedData->PurgeCacheForViewportChange(aSVGViewportSize,
-                                              aHasIntrinsicRatio);
-    }
-  }
-}

layout/painting/nsImageRenderer.h

@@ -248,8 +248,6 @@ class nsImageRenderer {
   ImgDrawResult PrepareResult() const { return mPrepareResult; }
   void SetExtendMode(mozilla::gfx::ExtendMode aMode) { mExtendMode = aMode; }
   void SetMaskOp(mozilla::StyleMaskMode aMaskOp) { mMaskOp = aMaskOp; }
-  void PurgeCacheForViewportChange(
-      const mozilla::Maybe<nsSize>& aSVGViewportSize, const bool aHasRatio);
   const nsSize& GetSize() const { return mSize; }
   mozilla::StyleImage::Tag GetType() const { return mType; }
   const mozilla::StyleGradient* GetGradientData() const {

layout/style/nsStyleStruct.cpp

@@ -1452,29 +1452,6 @@ bool StyleGradient::IsOpaque() const {
   return GradientItemsAreOpaque(AsConic().items.AsSpan());
 }
 
-// --------------------
-// CachedBorderImageData
-
-void CachedBorderImageData::PurgeCachedImages() {
-  MOZ_ASSERT(!ServoStyleSet::IsInServoTraversal());
-  MOZ_ASSERT(NS_IsMainThread());
-  mSubImages.Clear();
-}
-
-void CachedBorderImageData::PurgeCacheForViewportChange(
-    const Maybe<nsSize>& aSize, const bool aHasIntrinsicRatio) {
-  // If we're redrawing with a different viewport-size than we used for our
-  // cached subimages, then we can't trust that our subimages are valid;
-  // any percent sizes/positions in our SVG doc may be different now. Purge!
-  // (We don't have to purge if the SVG document has an intrinsic ratio,
-  // though, because the actual size of elements in SVG documant's coordinate
-  // axis are fixed in this case.)
-  if (aSize != mCachedSVGViewportSize && !aHasIntrinsicRatio) {
-    PurgeCachedImages();
-    SetCachedSVGViewportSize(aSize);
-  }
-}
-
 static int32_t ConvertToPixelCoord(const StyleNumberOrPercentage& aCoord,
                                    int32_t aPercentScale) {
   double pixelValue;

layout/style/nsStyleStruct.h

@@ -162,44 +162,6 @@ struct MOZ_NEEDS_MEMMOVABLE_MEMBERS nsStyleFont {
   RefPtr<nsAtom> mLanguage;
 };
 
-// TODO(emilio, bug 1564526): Evaluate whether this is still needed.
-struct CachedBorderImageData {
-  ~CachedBorderImageData() { PurgeCachedImages(); }
-
-  // Caller are expected to ensure that the value of aSize is different from the
-  // cached one since the method won't do the check.
-  void SetCachedSVGViewportSize(const mozilla::Maybe<nsSize>& aSize) {
-    mCachedSVGViewportSize = aSize;
-  }
-
-  const mozilla::Maybe<nsSize>& GetCachedSVGViewportSize() const {
-    return mCachedSVGViewportSize;
-  }
-
-  void PurgeCachedImages();
-
-  void SetSubImage(uint8_t aIndex, imgIContainer* aSubImage) {
-    mSubImages.EnsureLengthAtLeast(aIndex + 1);
-    mSubImages[aIndex] = aSubImage;
-  }
-  imgIContainer* GetSubImage(uint8_t aIndex) {
-    return mSubImages.SafeElementAt(aIndex);
-  }
-
-  // These methods are used for the caller to caches the sub images created
-  // during a border-image paint operation
-  void PurgeCacheForViewportChange(
-      const mozilla::Maybe<nsSize>& aSVGViewportSize,
-      const bool aHasIntrinsicRatio);
-
- private:
-  // If this is a SVG border-image, we save the size of the SVG viewport that
-  // we used when rasterizing any cached border-image subimages. (The viewport
-  // size matters for percent-valued sizes & positions in inner SVG doc).
-  mozilla::Maybe<nsSize> mCachedSVGViewportSize;
-  nsTArray<RefPtr<imgIContainer>> mSubImages;
-};
-
 struct nsStyleImageLayers {
   enum class LayerType : uint8_t { Background = 0, Mask };