Merge pull request #961 from kn-yami/issue908

implement missing parts of CSS mask

27 files changed, 574 insertions, 433 deletions

diff --git a/layout/base/nsCSSRendering.cpp b/layout/base/nsCSSRendering.cpp
index 71ebfad224..ff9edf7420 100644
--- a/layout/base/nsCSSRendering.cpp
+++ b/layout/base/nsCSSRendering.cpp
@@ -1803,6 +1803,44 @@ SetupDirtyRects(const nsRect& aBGClipArea, const nsRect& aCallerDirtyRect,
              "second should be empty if first is");
 }
 
+static bool
+IsSVGStyleGeometryBox(StyleGeometryBox aBox)
+{
+  return (aBox == StyleGeometryBox::Fill || aBox == StyleGeometryBox::Stroke ||
+          aBox == StyleGeometryBox::View);
+}
+
+static bool
+IsHTMLStyleGeometryBox(StyleGeometryBox aBox)
+{
+  return (aBox == StyleGeometryBox::Content ||
+          aBox == StyleGeometryBox::Padding ||
+          aBox == StyleGeometryBox::Border ||
+          aBox == StyleGeometryBox::Margin);
+}
+
+static StyleGeometryBox
+ComputeBoxValue(nsIFrame* aForFrame, StyleGeometryBox aBox)
+{
+  // Except <svg>, all svg elements are not associate with CSS layout box.
+  if (aForFrame->IsFrameOfType(nsIFrame::eSVG) &&
+      (aForFrame->GetType() != nsGkAtoms::svgOuterSVGFrame)) {
+    // For SVG elements without associated CSS layout box, the values
+    // content-box, padding-box, border-box and margin-box compute to fill-box.
+    if (IsHTMLStyleGeometryBox(aBox)) {
+      return StyleGeometryBox::Fill;
+    }
+  } else {
+    // For elements with associated CSS layout box, the values fill-box,
+    // stroke-box and view-box compute to the initial value of mask-clip.
+    if (IsSVGStyleGeometryBox(aBox)) {
+      return StyleGeometryBox::Border;
+    }
+  }
+
+  return aBox;
+}
+
 /* static */ void
 nsCSSRendering::GetImageLayerClip(const nsStyleImageLayers::Layer& aLayer,
                                   nsIFrame* aForFrame, const nsStyleBorder& aBorder,
@@ -1810,6 +1848,55 @@ nsCSSRendering::GetImageLayerClip(const nsStyleImageLayers::Layer& aLayer,
                                   bool aWillPaintBorder, nscoord aAppUnitsPerPixel,
                                   /* out */ ImageLayerClipState* aClipState)
 {
+  StyleGeometryBox layerClip = ComputeBoxValue(aForFrame, aLayer.mClip);
+
+  if (IsSVGStyleGeometryBox(layerClip)) {
+    MOZ_ASSERT(aForFrame->IsFrameOfType(nsIFrame::eSVG) &&
+               (aForFrame->GetType() != nsGkAtoms::svgOuterSVGFrame));
+
+    aClipState->mHasAdditionalBGClipArea = false;
+    aClipState->mCustomClip = false;
+
+    // The coordinate space of clipArea is svg user space.
+    nsRect clipArea =
+      nsLayoutUtils::ComputeGeometryBox(aForFrame, layerClip);
+
+    nsRect strokeBox = (layerClip == StyleGeometryBox::Stroke)
+      ? clipArea
+      : nsLayoutUtils::ComputeGeometryBox(aForFrame, StyleGeometryBox::Stroke);
+    nsRect clipAreaRelativeToStrokeBox = clipArea - strokeBox.TopLeft();
+
+    // aBorderArea is the stroke-box area in a coordinate space defined by
+    // the caller. This coordinate space can be svg user space of aForFrame,
+    // the space of aForFrame's reference-frame, or anything else.
+    //
+    // Which coordinate space chosen for aBorderArea is not matter. What
+    // matter is to ensure returning aClipState->mBGClipArea in the consistent
+    // coordiante space with aBorderArea. So we evaluate the position of clip
+    // area base on the position of aBorderArea here.
+    aClipState->mBGClipArea =
+      clipAreaRelativeToStrokeBox + aBorderArea.TopLeft();
+
+    SetupDirtyRects(aClipState->mBGClipArea, aCallerDirtyRect,
+                    aAppUnitsPerPixel, &aClipState->mDirtyRect,
+                    &aClipState->mDirtyRectGfx);
+    return;
+  }
+
+  if (layerClip == StyleGeometryBox::NoClip) {
+    aClipState->mBGClipArea = aCallerDirtyRect;
+    aClipState->mHasAdditionalBGClipArea = false;
+    aClipState->mCustomClip = false;
+
+    SetupDirtyRects(aClipState->mBGClipArea, aCallerDirtyRect,
+                    aAppUnitsPerPixel, &aClipState->mDirtyRect,
+                    &aClipState->mDirtyRectGfx);
+    return;
+  }
+
+  MOZ_ASSERT(!aForFrame->IsFrameOfType(nsIFrame::eSVG) ||
+             aForFrame->GetType() == nsGkAtoms::svgOuterSVGFrame);
+
   // Compute the outermost boundary of the area that might be painted.
   // Same coordinate space as aBorderArea.
   Sides skipSides = aForFrame->GetSkipSides();
@@ -1819,16 +1906,15 @@ nsCSSRendering::GetImageLayerClip(const nsStyleImageLayers::Layer& aLayer,
   bool haveRoundedCorners = GetRadii(aForFrame, aBorder, aBorderArea,
                                      clipBorderArea, aClipState->mRadii);
 
-  uint8_t backgroundClip = aLayer.mClip;
-
   bool isSolidBorder =
       aWillPaintBorder && IsOpaqueBorder(aBorder);
-  if (isSolidBorder && backgroundClip == NS_STYLE_IMAGELAYER_CLIP_BORDER) {
+  if (isSolidBorder && layerClip == StyleGeometryBox::Border) {
     // If we have rounded corners, we need to inflate the background
     // drawing area a bit to avoid seams between the border and
     // background.
-    backgroundClip = haveRoundedCorners ?
-      NS_STYLE_IMAGELAYER_CLIP_MOZ_ALMOST_PADDING : NS_STYLE_IMAGELAYER_CLIP_PADDING;
+    layerClip = haveRoundedCorners
+                     ? StyleGeometryBox::MozAlmostPadding
+                     : StyleGeometryBox::Padding;
   }
 
   aClipState->mBGClipArea = clipBorderArea;
@@ -1844,7 +1930,7 @@ nsCSSRendering::GetImageLayerClip(const nsStyleImageLayers::Layer& aLayer,
     // but the background is also clipped at a non-scrolling 'padding-box'
     // like the content. (See below.)
     // Therefore, only 'content-box' makes a difference here.
-    if (backgroundClip == NS_STYLE_IMAGELAYER_CLIP_CONTENT) {
+    if (layerClip == StyleGeometryBox::Content) {
       nsIScrollableFrame* scrollableFrame = do_QueryFrame(aForFrame);
       // Clip at a rectangle attached to the scrolled content.
       aClipState->mHasAdditionalBGClipArea = true;
@@ -1864,22 +1950,30 @@ nsCSSRendering::GetImageLayerClip(const nsStyleImageLayers::Layer& aLayer,
 
     // Also clip at a non-scrolling, rounded-corner 'padding-box',
     // same as the scrolled content because of the 'overflow' property.
-    backgroundClip = NS_STYLE_IMAGELAYER_CLIP_PADDING;
+    layerClip = StyleGeometryBox::Padding;
   }
 
-  if (backgroundClip != NS_STYLE_IMAGELAYER_CLIP_BORDER &&
-      backgroundClip != NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+  // See the comment of StyleGeometryBox::Margin.
+  // Hitting this assertion means we decide to turn on margin-box support for
+  // positioned mask from CSS parser and style system. In this case, you
+  // should *inflate* mBGClipArea by the margin returning from
+  // aForFrame->GetUsedMargin() in the code chunk bellow.
+  MOZ_ASSERT(layerClip != StyleGeometryBox::Margin,
+             "StyleGeometryBox::Margin rendering is not supported yet.\n");
+
+  if (layerClip != StyleGeometryBox::Border &&
+      layerClip != StyleGeometryBox::Text) {
     nsMargin border = aForFrame->GetUsedBorder();
-    if (backgroundClip == NS_STYLE_IMAGELAYER_CLIP_MOZ_ALMOST_PADDING) {
+    if (layerClip == StyleGeometryBox::MozAlmostPadding) {
       // Reduce |border| by 1px (device pixels) on all sides, if
       // possible, so that we don't get antialiasing seams between the
-      // background and border.
+      // {background|mask} and border.
       border.top = std::max(0, border.top - aAppUnitsPerPixel);
       border.right = std::max(0, border.right - aAppUnitsPerPixel);
       border.bottom = std::max(0, border.bottom - aAppUnitsPerPixel);
       border.left = std::max(0, border.left - aAppUnitsPerPixel);
-    } else if (backgroundClip != NS_STYLE_IMAGELAYER_CLIP_PADDING) {
-      NS_ASSERTION(backgroundClip == NS_STYLE_IMAGELAYER_CLIP_CONTENT,
+    } else if (layerClip != StyleGeometryBox::Padding) {
+      NS_ASSERTION(layerClip == StyleGeometryBox::Content,
                    "unexpected background-clip");
       border += aForFrame->GetUsedPadding();
     }
@@ -3163,7 +3257,7 @@ nsCSSRendering::PaintBackgroundWithSC(const PaintBGParams& aParams,
 
   if (drawBackgroundImage) {
     bool clipSet = false;
-    uint8_t currentBackgroundClip = NS_STYLE_IMAGELAYER_CLIP_BORDER;
+    StyleGeometryBox currentBackgroundClip = StyleGeometryBox::Border;
     NS_FOR_VISIBLE_IMAGE_LAYERS_BACK_TO_FRONT_WITH_RANGE(i, layers, layers.mImageCount - 1,
                                                          nLayers + (layers.mImageCount -
                                                          startLayer - 1)) {
@@ -3239,16 +3333,43 @@ nsCSSRendering::ComputeImageLayerPositioningArea(nsPresContext* aPresContext,
                                                  nsIFrame** aAttachedToFrame,
                                                  bool* aOutIsTransformedFixed)
 {
-  // Compute background origin area relative to aBorderArea now as we may need
-  // it to compute the effective image size for a CSS gradient.
-  nsRect bgPositioningArea;
+  // Compute {background|mask} origin area relative to aBorderArea now as we
+  // may need  it to compute the effective image size for a CSS gradient.
+  nsRect positionArea;
+
+  StyleGeometryBox layerOrigin =
+    ComputeBoxValue(aForFrame, aLayer.mOrigin);
+
+  if (IsSVGStyleGeometryBox(layerOrigin)) {
+    MOZ_ASSERT(aForFrame->IsFrameOfType(nsIFrame::eSVG) &&
+               (aForFrame->GetType() != nsGkAtoms::svgOuterSVGFrame));
+    *aAttachedToFrame = aForFrame;
+
+    positionArea =
+      nsLayoutUtils::ComputeGeometryBox(aForFrame, layerOrigin);
+
+    nsPoint toStrokeBoxOffset = nsPoint(0, 0);
+    if (layerOrigin != StyleGeometryBox::Stroke) {
+      nsRect strokeBox =
+        nsLayoutUtils::ComputeGeometryBox(aForFrame,
+                                          StyleGeometryBox::Stroke);
+      toStrokeBoxOffset = positionArea.TopLeft() - strokeBox.TopLeft();
+    }
+
+    // For SVG frames, the return value is relative to the stroke box
+    return nsRect(toStrokeBoxOffset, positionArea.Size());
+  }
+
+  MOZ_ASSERT(!aForFrame->IsFrameOfType(nsIFrame::eSVG) ||
+             aForFrame->GetType() == nsGkAtoms::svgOuterSVGFrame);
+
 
   nsIAtom* frameType = aForFrame->GetType();
   nsIFrame* geometryFrame = aForFrame;
   if (MOZ_UNLIKELY(frameType == nsGkAtoms::scrollFrame &&
                    NS_STYLE_IMAGELAYER_ATTACHMENT_LOCAL == aLayer.mAttachment)) {
     nsIScrollableFrame* scrollableFrame = do_QueryFrame(aForFrame);
-    bgPositioningArea = nsRect(
+    positionArea = nsRect(
       scrollableFrame->GetScrolledFrame()->GetPosition()
         // For the dir=rtl case:
         + scrollableFrame->GetScrollRange().TopLeft(),
@@ -3256,20 +3377,20 @@ nsCSSRendering::ComputeImageLayerPositioningArea(nsPresContext* aPresContext,
     // The ScrolledRect’s size does not include the borders or scrollbars,
     // reverse the handling of background-origin
     // compared to the common case below.
-    if (aLayer.mOrigin == NS_STYLE_IMAGELAYER_ORIGIN_BORDER) {
+    if (layerOrigin == StyleGeometryBox::Border) {
       nsMargin border = geometryFrame->GetUsedBorder();
       border.ApplySkipSides(geometryFrame->GetSkipSides());
-      bgPositioningArea.Inflate(border);
-      bgPositioningArea.Inflate(scrollableFrame->GetActualScrollbarSizes());
-    } else if (aLayer.mOrigin != NS_STYLE_IMAGELAYER_ORIGIN_PADDING) {
+      positionArea.Inflate(border);
+      positionArea.Inflate(scrollableFrame->GetActualScrollbarSizes());
+    } else if (layerOrigin != StyleGeometryBox::Padding) {
       nsMargin padding = geometryFrame->GetUsedPadding();
       padding.ApplySkipSides(geometryFrame->GetSkipSides());
-      bgPositioningArea.Deflate(padding);
-      NS_ASSERTION(aLayer.mOrigin == NS_STYLE_IMAGELAYER_ORIGIN_CONTENT,
+      positionArea.Deflate(padding);
+      NS_ASSERTION(layerOrigin == StyleGeometryBox::Content,
                    "unknown background-origin value");
     }
     *aAttachedToFrame = aForFrame;
-    return bgPositioningArea;
+    return positionArea;
   }
 
   if (MOZ_UNLIKELY(frameType == nsGkAtoms::canvasFrame)) {
@@ -3279,25 +3400,31 @@ nsCSSRendering::ComputeImageLayerPositioningArea(nsPresContext* aPresContext,
     // finished and this page only displays the continuations of
     // absolutely positioned content).
     if (geometryFrame) {
-      bgPositioningArea = geometryFrame->GetRect();
+       positionArea = geometryFrame->GetRect();
     }
   } else {
-    bgPositioningArea = nsRect(nsPoint(0,0), aBorderArea.Size());
+    positionArea = nsRect(nsPoint(0,0), aBorderArea.Size());
   }
 
-  // Background images are tiled over the 'background-clip' area
-  // but the origin of the tiling is based on the 'background-origin' area
-  // XXX: Bug 1303623 will bring in new origin value, we should iterate from
-  // NS_STYLE_IMAGELAYER_ORIGIN_MARGIN instead of
-  // NS_STYLE_IMAGELAYER_ORIGIN_BORDER.
-  if (aLayer.mOrigin != NS_STYLE_IMAGELAYER_ORIGIN_BORDER && geometryFrame) {
+  // See the comment of StyleGeometryBox::Margin.
+  // Hitting this assertion means we decide to turn on margin-box support for
+  // positioned mask from CSS parser and style system. In this case, you
+  // should *inflate* positionArea by the margin returning from
+  // geometryFrame->GetUsedMargin() in the code chunk bellow.
+  MOZ_ASSERT(aLayer.mOrigin != StyleGeometryBox::Margin,
+             "StyleGeometryBox::Margin rendering is not supported yet.\n");
+
+  // {background|mask} images are tiled over the '{background|mask}-clip' area
+  // but the origin of the tiling is based on the '{background|mask}-origin'
+  // area.
+  if (layerOrigin != StyleGeometryBox::Border && geometryFrame) {
     nsMargin border = geometryFrame->GetUsedBorder();
-    if (aLayer.mOrigin != NS_STYLE_IMAGELAYER_ORIGIN_PADDING) {
+    if (layerOrigin != StyleGeometryBox::Padding) {
       border += geometryFrame->GetUsedPadding();
-      NS_ASSERTION(aLayer.mOrigin == NS_STYLE_IMAGELAYER_ORIGIN_CONTENT,
+      NS_ASSERTION(layerOrigin == StyleGeometryBox::Content,
                    "unknown background-origin value");
     }
-    bgPositioningArea.Deflate(border);
+    positionArea.Deflate(border);
   }
 
   nsIFrame* attachedToFrame = aForFrame;
@@ -3325,7 +3452,7 @@ nsCSSRendering::ComputeImageLayerPositioningArea(nsPresContext* aPresContext,
     } else {
       // Set the background positioning area to the viewport's area
       // (relative to aForFrame)
-      bgPositioningArea =
+      positionArea =
         nsRect(-aForFrame->GetOffsetTo(attachedToFrame), attachedToFrame->GetSize());
 
       if (!pageContentFrame) {
@@ -3334,14 +3461,14 @@ nsCSSRendering::ComputeImageLayerPositioningArea(nsPresContext* aPresContext,
           aPresContext->PresShell()->GetRootScrollFrameAsScrollable();
         if (scrollableFrame) {
           nsMargin scrollbars = scrollableFrame->GetActualScrollbarSizes();
-          bgPositioningArea.Deflate(scrollbars);
+          positionArea.Deflate(scrollbars);
         }
       }
     }
   }
   *aAttachedToFrame = attachedToFrame;
 
-  return bgPositioningArea;
+  return positionArea;
 }
 
 // Implementation of the formula for computation of background-repeat round
@@ -3569,7 +3696,7 @@ nsCSSRendering::PrepareImageLayer(nsPresContext* aPresContext,
   bool transformedFixed = false;
   // Compute background origin area relative to aBorderArea now as we may need
   // it to compute the effective image size for a CSS gradient.
-  nsRect bgPositioningArea =
+  nsRect positionArea =
     ComputeImageLayerPositioningArea(aPresContext, aForFrame, aBorderArea,
                                      aLayer, &attachedToFrame, &transformedFixed);
   if (aOutIsTransformedFixed) {
@@ -3594,7 +3721,7 @@ nsCSSRendering::PrepareImageLayer(nsPresContext* aPresContext,
       // not a pure optimization since it can affect the values of pixels at the
       // edge of the viewport --- whether they're sampled from a putative "next
       // tile" or not.)
-      bgClipRect.IntersectRect(bgClipRect, bgPositioningArea + aBorderArea.TopLeft());
+      bgClipRect.IntersectRect(bgClipRect, positionArea + aBorderArea.TopLeft());
     }
   }
 
@@ -3605,7 +3732,7 @@ nsCSSRendering::PrepareImageLayer(nsPresContext* aPresContext,
   // Also as required for proper background positioning when background-position
   // is defined with percentages.
   CSSSizeOrRatio intrinsicSize = state.mImageRenderer.ComputeIntrinsicSize();
-  nsSize bgPositionSize = bgPositioningArea.Size();
+  nsSize bgPositionSize = positionArea.Size();
   nsSize imageSize = ComputeDrawnSizeForBackground(intrinsicSize,
                                                    bgPositionSize,
                                                    aLayer.mSize,
@@ -3650,8 +3777,8 @@ nsCSSRendering::PrepareImageLayer(nsPresContext* aPresContext,
     }
   }
 
-  imageTopLeft += bgPositioningArea.TopLeft();
-  state.mAnchor += bgPositioningArea.TopLeft();
+  imageTopLeft += positionArea.TopLeft();
+  state.mAnchor += positionArea.TopLeft();
   state.mDestArea = nsRect(imageTopLeft + aBorderArea.TopLeft(), imageSize);
   state.mFillArea = state.mDestArea;
 
diff --git a/layout/base/nsDisplayList.cpp b/layout/base/nsDisplayList.cpp
index 2b9ad7ff81..d619576baf 100644
--- a/layout/base/nsDisplayList.cpp
+++ b/layout/base/nsDisplayList.cpp
@@ -3014,7 +3014,7 @@ nsDisplayBackgroundImage::ComputeVisibility(nsDisplayListBuilder* aBuilder,
 
 /* static */ nsRegion
 nsDisplayBackgroundImage::GetInsideClipRegion(nsDisplayItem* aItem,
-                                              uint8_t aClip,
+                                              StyleGeometryBox aClip,
                                               const nsRect& aRect,
                                               const nsRect& aBackgroundRect)
 {
@@ -3028,10 +3028,10 @@ nsDisplayBackgroundImage::GetInsideClipRegion(nsDisplayItem* aItem,
   if (frame->GetType() == nsGkAtoms::canvasFrame) {
     nsCanvasFrame* canvasFrame = static_cast<nsCanvasFrame*>(frame);
     clipRect = canvasFrame->CanvasArea() + aItem->ToReferenceFrame();
-  } else if (aClip == NS_STYLE_IMAGELAYER_CLIP_PADDING ||
-             aClip == NS_STYLE_IMAGELAYER_CLIP_CONTENT) {
+  } else if (aClip == StyleGeometryBox::Padding ||
+             aClip == StyleGeometryBox::Content) {
     nsMargin border = frame->GetUsedBorder();
-    if (aClip == NS_STYLE_IMAGELAYER_CLIP_CONTENT) {
+    if (aClip == StyleGeometryBox::Content) {
       border += frame->GetUsedPadding();
     }
     border.ApplySkipSides(frame->GetSkipSides());
@@ -3064,7 +3064,7 @@ nsDisplayBackgroundImage::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
     if (layer.mImage.IsOpaque() && layer.mBlendMode == NS_STYLE_BLEND_NORMAL &&
         layer.mRepeat.mXRepeat != NS_STYLE_IMAGELAYER_REPEAT_SPACE &&
         layer.mRepeat.mYRepeat != NS_STYLE_IMAGELAYER_REPEAT_SPACE &&
-        layer.mClip != NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+        layer.mClip != StyleGeometryBox::Text) {
       result = GetInsideClipRegion(this, layer.mClip, mBounds, mBackgroundRect);
     }
   }
@@ -3143,9 +3143,9 @@ nsDisplayBackgroundImage::PaintInternal(nsDisplayListBuilder* aBuilder,
   CheckForBorderItem(this, flags);
 
   gfxContext* ctx = aCtx->ThebesContext();
-  uint8_t clip = mBackgroundStyle->mImage.mLayers[mLayer].mClip;
+  StyleGeometryBox clip = mBackgroundStyle->mImage.mLayers[mLayer].mClip;
 
-  if (clip == NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+  if (clip == StyleGeometryBox::Text) {
     if (!GenerateAndPushTextMask(mFrame, aCtx, mBackgroundRect, aBuilder)) {
       return;
     }
@@ -3161,7 +3161,7 @@ nsDisplayBackgroundImage::PaintInternal(nsDisplayListBuilder* aBuilder,
   image::DrawResult result =
     nsCSSRendering::PaintBackground(params);
 
-  if (clip == NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+  if (clip == StyleGeometryBox::Text) {
     ctx->PopGroupAndBlend();
   }
 
@@ -3583,8 +3583,8 @@ nsDisplayBackgroundColor::Paint(nsDisplayListBuilder* aBuilder,
     nsLayoutUtils::RectToGfxRect(mBackgroundRect,
                                  mFrame->PresContext()->AppUnitsPerDevPixel());
 
-  uint8_t clip = mBackgroundStyle->mImage.mLayers[0].mClip;
-  if (clip == NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+  StyleGeometryBox clip = mBackgroundStyle->mImage.mLayers[0].mClip;
+  if (clip == StyleGeometryBox::Text) {
     if (!GenerateAndPushTextMask(mFrame, aCtx, mBackgroundRect, aBuilder)) {
       return;
     }
@@ -3618,7 +3618,7 @@ nsDisplayBackgroundColor::GetOpaqueRegion(nsDisplayListBuilder* aBuilder,
 
 
   const nsStyleImageLayers::Layer& bottomLayer = mBackgroundStyle->BottomLayer();
-  if (bottomLayer.mClip == NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+  if (bottomLayer.mClip == StyleGeometryBox::Text) {
     return nsRegion();
   }
 
diff --git a/layout/base/nsDisplayList.h b/layout/base/nsDisplayList.h
index 9603a95b81..c9f773f5b6 100644
--- a/layout/base/nsDisplayList.h
+++ b/layout/base/nsDisplayList.h
@@ -2713,6 +2713,8 @@ private:
  */
 class nsDisplayBackgroundImage : public nsDisplayImageContainer {
 public:
+  typedef mozilla::StyleGeometryBox StyleGeometryBox;
+
   /**
    * aLayer signifies which background layer this item represents.
    * aIsThemed should be the value of aFrame->IsThemed.
@@ -2790,8 +2792,10 @@ public:
   virtual already_AddRefed<imgIContainer> GetImage() override;
   virtual nsRect GetDestRect() override;
 
-  static nsRegion GetInsideClipRegion(nsDisplayItem* aItem, uint8_t aClip,
-                                      const nsRect& aRect, const nsRect& aBackgroundRect);
+  static nsRegion GetInsideClipRegion(nsDisplayItem* aItem,
+                                      StyleGeometryBox aClip,
+                                      const nsRect& aRect,
+                                      const nsRect& aBackgroundRect);
 
   virtual bool ShouldFixToViewport(nsDisplayListBuilder* aBuilder) override;
 
diff --git a/layout/base/nsLayoutUtils.cpp b/layout/base/nsLayoutUtils.cpp
index 19200d5a72..f0341f9eff 100644
--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -117,6 +117,7 @@
 #include "mozilla/StyleSetHandle.h"
 #include "mozilla/StyleSetHandleInlines.h"
 #include "RegionBuilder.h"
+#include "SVGSVGElement.h"
 
 #ifdef MOZ_XUL
 #include "nsXULPopupManager.h"
@@ -6935,7 +6936,7 @@ nsLayoutUtils::GetFrameTransparency(nsIFrame* aBackgroundFrame,
   const nsStyleBackground* bg = bgSC->StyleBackground();
   if (NS_GET_A(bg->mBackgroundColor) < 255 ||
       // bottom layer's clip is used for the color
-      bg->BottomLayer().mClip != NS_STYLE_IMAGELAYER_CLIP_BORDER)
+      bg->BottomLayer().mClip != StyleGeometryBox::Border)
     return eTransparencyTransparent;
   return eTransparencyOpaque;
 }
@@ -9293,3 +9294,127 @@ nsLayoutUtils::IsInvisibleBreak(nsINode* aNode, nsIFrame** aNextLineFrame)
 
   return lineNonEmpty;
 }
+
+static nsRect
+ComputeSVGReferenceRect(nsIFrame* aFrame,
+                        StyleGeometryBox aGeometryBox)
+{
+  MOZ_ASSERT(aFrame->GetContent()->IsSVGElement());
+  nsRect r;
+
+  // For SVG elements without associated CSS layout box, the used value for
+  // content-box, padding-box, border-box and margin-box is fill-box.
+  switch (aGeometryBox) {
+    case StyleGeometryBox::Stroke: {
+      // XXX Bug 1299876
+      // The size of srtoke-box is not correct if this graphic element has
+      // specific stroke-linejoin or stroke-linecap.
+      gfxRect bbox = nsSVGUtils::GetBBox(aFrame,
+                nsSVGUtils::eBBoxIncludeFill | nsSVGUtils::eBBoxIncludeStroke);
+      r = nsLayoutUtils::RoundGfxRectToAppRect(bbox,
+                                         nsPresContext::AppUnitsPerCSSPixel());
+      break;
+    }
+    case StyleGeometryBox::View: {
+      nsIContent* content = aFrame->GetContent();
+      nsSVGElement* element = static_cast<nsSVGElement*>(content);
+      SVGSVGElement* svgElement = element->GetCtx();
+      MOZ_ASSERT(svgElement);
+
+      if (svgElement && svgElement->HasViewBoxRect()) {
+        // If a ‘viewBox‘ attribute is specified for the SVG viewport creating
+        // element:
+        // 1. The reference box is positioned at the origin of the coordinate
+        //    system established by the ‘viewBox‘ attribute.
+        // 2. The dimension of the reference box is set to the width and height
+        //    values of the ‘viewBox‘ attribute.
+        nsSVGViewBox* viewBox = svgElement->GetViewBox();
+        const nsSVGViewBoxRect& value = viewBox->GetAnimValue();
+        r = nsRect(nsPresContext::CSSPixelsToAppUnits(value.x),
+                   nsPresContext::CSSPixelsToAppUnits(value.y),
+                   nsPresContext::CSSPixelsToAppUnits(value.width),
+                   nsPresContext::CSSPixelsToAppUnits(value.height));
+      } else {
+        // No viewBox is specified, uses the nearest SVG viewport as reference
+        // box.
+        svgFloatSize viewportSize = svgElement->GetViewportSize();
+        r = nsRect(0, 0,
+                   nsPresContext::CSSPixelsToAppUnits(viewportSize.width),
+                   nsPresContext::CSSPixelsToAppUnits(viewportSize.height));
+      }
+
+      break;
+    }
+    case StyleGeometryBox::NoBox:
+    case StyleGeometryBox::Border:
+    case StyleGeometryBox::Content:
+    case StyleGeometryBox::Padding:
+    case StyleGeometryBox::Margin:
+    case StyleGeometryBox::Fill: {
+      gfxRect bbox = nsSVGUtils::GetBBox(aFrame,
+                                         nsSVGUtils::eBBoxIncludeFill);
+      r = nsLayoutUtils::RoundGfxRectToAppRect(bbox,
+                                         nsPresContext::AppUnitsPerCSSPixel());
+      break;
+    }
+    default:{
+      MOZ_ASSERT_UNREACHABLE("unknown StyleGeometryBox type");
+      gfxRect bbox = nsSVGUtils::GetBBox(aFrame,
+                                         nsSVGUtils::eBBoxIncludeFill);
+      r = nsLayoutUtils::RoundGfxRectToAppRect(bbox,
+                                         nsPresContext::AppUnitsPerCSSPixel());
+      break;
+    }
+  }
+
+  return r;
+}
+
+static nsRect
+ComputeHTMLReferenceRect(nsIFrame* aFrame,
+                         StyleGeometryBox aGeometryBox)
+{
+  nsRect r;
+
+  // For elements with associated CSS layout box, the used value for fill-box,
+  // stroke-box and view-box is border-box.
+  switch (aGeometryBox) {
+    case StyleGeometryBox::Content:
+      r = aFrame->GetContentRectRelativeToSelf();
+      break;
+    case StyleGeometryBox::Padding:
+      r = aFrame->GetPaddingRectRelativeToSelf();
+      break;
+    case StyleGeometryBox::Margin:
+      r = aFrame->GetMarginRectRelativeToSelf();
+      break;
+    case StyleGeometryBox::NoBox:
+    case StyleGeometryBox::Border:
+    case StyleGeometryBox::Fill:
+    case StyleGeometryBox::Stroke:
+    case StyleGeometryBox::View:
+      r = aFrame->GetRectRelativeToSelf();
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("unknown StyleGeometryBox type");
+      r = aFrame->GetRectRelativeToSelf();
+      break;
+  }
+
+  return r;
+}
+
+/* static */ nsRect
+nsLayoutUtils::ComputeGeometryBox(nsIFrame* aFrame,
+                                  StyleGeometryBox aGeometryBox)
+{
+  // We use ComputeSVGReferenceRect for all SVG elements, except <svg>
+  // element, which does have an associated CSS layout box. In this case we
+  // should still use ComputeHTMLReferenceRect for region computing.
+  nsRect r = aFrame->IsFrameOfType(nsIFrame::eSVG) &&
+             (aFrame->GetType() != nsGkAtoms::svgOuterSVGFrame)
+             ? ComputeSVGReferenceRect(aFrame, aGeometryBox)
+             : ComputeHTMLReferenceRect(aFrame, aGeometryBox);
+
+  return r;
+}
diff --git a/layout/base/nsLayoutUtils.h b/layout/base/nsLayoutUtils.h
index 97fc410b0a..63253fd100 100644
--- a/layout/base/nsLayoutUtils.h
+++ b/layout/base/nsLayoutUtils.h
@@ -30,6 +30,7 @@
 #include "mozilla/ReflowOutput.h"
 #include "ImageContainer.h"
 #include "gfx2DGlue.h"
+#include "nsStyleConsts.h"
 
 #include <limits>
 #include <algorithm>
@@ -152,6 +153,7 @@ public:
   typedef mozilla::CSSRect CSSRect;
   typedef mozilla::ScreenMargin ScreenMargin;
   typedef mozilla::LayoutDeviceIntSize LayoutDeviceIntSize;
+  typedef mozilla::StyleGeometryBox StyleGeometryBox;
 
   /**
    * Finds previously assigned ViewID for the given content element, if any.
@@ -2870,6 +2872,9 @@ public:
    */
   static bool IsInvisibleBreak(nsINode* aNode, nsIFrame** aNextLineFrame = nullptr);
 
+  static nsRect ComputeGeometryBox(nsIFrame* aFrame,
+                                   StyleGeometryBox aGeometryBox);
+
 private:
   static uint32_t sFontSizeInflationEmPerLine;
   static uint32_t sFontSizeInflationMinTwips;
diff --git a/layout/generic/nsTextFrame.cpp b/layout/generic/nsTextFrame.cpp
index fa31443fdd..3288d3f2e4 100644
--- a/layout/generic/nsTextFrame.cpp
+++ b/layout/generic/nsTextFrame.cpp
@@ -6715,7 +6715,7 @@ ShouldDrawSelection(const nsIFrame* aFrame)
   const nsStyleBackground* bg = aFrame->StyleContext()->StyleBackground();
   const nsStyleImageLayers& layers = bg->mImage;
   NS_FOR_VISIBLE_IMAGE_LAYERS_BACK_TO_FRONT(i, layers) {
-    if (layers.mLayers[i].mClip == NS_STYLE_IMAGELAYER_CLIP_TEXT) {
+    if (layers.mLayers[i].mClip == StyleGeometryBox::Text) {
       return false;
     }
   }
diff --git a/layout/inspector/inDOMUtils.cpp b/layout/inspector/inDOMUtils.cpp
index 9f1dcaad3f..e212e20df0 100644
--- a/layout/inspector/inDOMUtils.cpp
+++ b/layout/inspector/inDOMUtils.cpp
@@ -784,12 +784,10 @@ PropertySupportsVariant(nsCSSPropertyID aPropertyID, uint32_t aVariant)
       case eCSSProperty_background_position_x:
       case eCSSProperty_background_position_y:
       case eCSSProperty_background_size:
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
       case eCSSProperty_mask_position:
       case eCSSProperty_mask_position_x:
       case eCSSProperty_mask_position_y:
       case eCSSProperty_mask_size:
-#endif
       case eCSSProperty_grid_auto_columns:
       case eCSSProperty_grid_auto_rows:
       case eCSSProperty_grid_template_columns:
diff --git a/layout/style/Declaration.cpp b/layout/style/Declaration.cpp
index c67f6b2a2e..b2de159ed3 100644
--- a/layout/style/Declaration.cpp
+++ b/layout/style/Declaration.cpp
@@ -395,28 +395,25 @@ Declaration::GetImageLayerValue(
                origin->mValue.GetUnit() == eCSSUnit_Enumerated,
                "should not have inherit/initial within list");
 
-    int32_t originDefaultValue =
+    StyleGeometryBox originDefaultValue =
       (aTable == nsStyleImageLayers::kBackgroundLayerTable)
-      ? NS_STYLE_IMAGELAYER_ORIGIN_PADDING : NS_STYLE_IMAGELAYER_ORIGIN_BORDER;
-    if (clip->mValue.GetIntValue() != NS_STYLE_IMAGELAYER_CLIP_BORDER ||
-        origin->mValue.GetIntValue() != originDefaultValue) {
+      ? StyleGeometryBox::Padding : StyleGeometryBox::Border;
+    if (static_cast<StyleGeometryBox>(clip->mValue.GetIntValue()) !=
+        StyleGeometryBox::Border ||
+        static_cast<StyleGeometryBox>(origin->mValue.GetIntValue()) !=
+        originDefaultValue) {
 #ifdef DEBUG
-      for (size_t i = 0; nsCSSProps::kImageLayerOriginKTable[i].mValue != -1; i++) {
+      const nsCSSProps::KTableEntry* originTable =
+        nsCSSProps::kKeywordTableTable[aTable[nsStyleImageLayers::origin]];
+      const nsCSSProps::KTableEntry* clipTable =
+        nsCSSProps::kKeywordTableTable[aTable[nsStyleImageLayers::clip]];
+      for (size_t i = 0; originTable[i].mValue != -1; i++) {
         // For each keyword & value in kOriginKTable, ensure that
         // kBackgroundKTable has a matching entry at the same position.
-        MOZ_ASSERT(nsCSSProps::kImageLayerOriginKTable[i].mKeyword ==
-                   nsCSSProps::kBackgroundClipKTable[i].mKeyword);
-        MOZ_ASSERT(nsCSSProps::kImageLayerOriginKTable[i].mValue ==
-                   nsCSSProps::kBackgroundClipKTable[i].mValue);
+        MOZ_ASSERT(originTable[i].mKeyword == clipTable[i].mKeyword);
+        MOZ_ASSERT(originTable[i].mValue == clipTable[i].mValue);
       }
 #endif
-      static_assert(NS_STYLE_IMAGELAYER_CLIP_BORDER ==
-                    NS_STYLE_IMAGELAYER_ORIGIN_BORDER &&
-                    NS_STYLE_IMAGELAYER_CLIP_PADDING ==
-                    NS_STYLE_IMAGELAYER_ORIGIN_PADDING &&
-                    NS_STYLE_IMAGELAYER_CLIP_CONTENT ==
-                    NS_STYLE_IMAGELAYER_ORIGIN_CONTENT,
-                    "mask-clip and mask-origin style constants must agree");
       aValue.Append(char16_t(' '));
       origin->mValue.AppendToString(aTable[nsStyleImageLayers::origin], aValue,
                                     aSerialization);
@@ -462,11 +459,7 @@ Declaration::GetImageLayerValue(
         }
       // This layer is an mask layer
       } else {
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
         MOZ_ASSERT(aTable == nsStyleImageLayers::kMaskLayerTable);
-#else
-        MOZ_ASSERT_UNREACHABLE("Should never get here when mask-as-shorthand is disable");
-#endif
         if (repeat || positionX || positionY || clip || origin || size ||
             composite || mode) {
           // Uneven length lists, so can't be serialized as shorthand.
@@ -487,11 +480,7 @@ Declaration::GetImageLayerValue(
       }
     // This layer is an mask layer
     } else {
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
       MOZ_ASSERT(aTable == nsStyleImageLayers::kMaskLayerTable);
-#else
-      MOZ_ASSERT_UNREACHABLE("Should never get here when mask-as-shorthand is disable");
-#endif
       if (!repeat || !positionX || !positionY || !clip || !origin || !size ||
           !composite || !mode) {
         // Uneven length lists, so can't be serialized as shorthand.
@@ -817,7 +806,6 @@ Declaration::GetPropertyValueInternal(
                                  nsStyleImageLayers::kBackgroundLayerTable);
       break;
     }
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
     case eCSSProperty_mask: {
       GetImageLayerValue(data, aValue, aSerialization,
                          nsStyleImageLayers::kMaskLayerTable);
@@ -828,7 +816,6 @@ Declaration::GetPropertyValueInternal(
                                  nsStyleImageLayers::kMaskLayerTable);
       break;
     }
-#endif
     case eCSSProperty_font: {
       // systemFont might not be present; other values are guaranteed to be
       // available based on the shorthand check at the beginning of the
diff --git a/layout/style/StyleAnimationValue.cpp b/layout/style/StyleAnimationValue.cpp
index eb34c3d832..a0f52b4ea1 100644
--- a/layout/style/StyleAnimationValue.cpp
+++ b/layout/style/StyleAnimationValue.cpp
@@ -4255,7 +4255,6 @@ StyleAnimationValue::ExtractComputedValue(nsCSSPropertyID aProperty,
 
 
         }
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
         case eCSSProperty_mask_position_x: {
           const nsStyleImageLayers& layers =
             static_cast<const nsStyleSVGReset*>(styleStruct)->mMask;
@@ -4269,21 +4268,18 @@ StyleAnimationValue::ExtractComputedValue(nsCSSPropertyID aProperty,
 
           break;
         }
-#endif
         case eCSSProperty_background_size: {
           const nsStyleImageLayers& layers =
             static_cast<const nsStyleBackground*>(styleStruct)->mImage;
           ExtractImageLayerSizePairList(layers, aComputedValue);
           break;
         }
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
         case eCSSProperty_mask_size: {
           const nsStyleImageLayers& layers =
             static_cast<const nsStyleSVGReset*>(styleStruct)->mMask;
           ExtractImageLayerSizePairList(layers, aComputedValue);
           break;
         }
-#endif
 
         case eCSSProperty_clip_path: {
           const nsStyleSVGReset* svgReset =
diff --git a/layout/style/nsCSSDataBlock.cpp b/layout/style/nsCSSDataBlock.cpp
index fe2dc621a5..1dfdaed0ee 100644
--- a/layout/style/nsCSSDataBlock.cpp
+++ b/layout/style/nsCSSDataBlock.cpp
@@ -61,7 +61,6 @@ TryToStartImageLoadOnValue(const nsCSSValue& aValue, nsIDocument* aDocument,
   MOZ_ASSERT(aDocument);
 
   if (aValue.GetUnit() == eCSSUnit_URL) {
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
     // The 'mask-image' property accepts local reference URIs.
     // For example,
     //   mask-image: url(#mask_id); // refer to a SVG mask element, whose id is
@@ -94,7 +93,6 @@ TryToStartImageLoadOnValue(const nsCSSValue& aValue, nsIDocument* aDocument,
         }
       }
     }
-#endif
     aValue.StartImageLoad(aDocument);
     if (aForTokenStream && aContext) {
       CSSVariableImageTable::Add(aContext, aProperty,
diff --git a/layout/style/nsCSSKeywordList.h b/layout/style/nsCSSKeywordList.h
index 94968faca3..34a46ffceb 100644
--- a/layout/style/nsCSSKeywordList.h
+++ b/layout/style/nsCSSKeywordList.h
@@ -405,6 +405,7 @@ CSS_KEY(n-resize, n_resize)
 CSS_KEY(narrower, narrower)
 CSS_KEY(ne-resize, ne_resize)
 CSS_KEY(nesw-resize, nesw_resize)
+CSS_KEY(no-clip, no_clip)
 CSS_KEY(no-close-quote, no_close_quote)
 CSS_KEY(no-common-ligatures, no_common_ligatures)
 CSS_KEY(no-contextual, no_contextual)
diff --git a/layout/style/nsCSSParser.cpp b/layout/style/nsCSSParser.cpp
index 736c66f87a..a8309314f8 100644
--- a/layout/style/nsCSSParser.cpp
+++ b/layout/style/nsCSSParser.cpp
@@ -12005,7 +12005,6 @@ CSSParserImpl::ParsePropertyByFunction(nsCSSPropertyID aPropID)
     return ParsePaintOrder();
   case eCSSProperty_scroll_snap_type:
     return ParseScrollSnapType();
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
   case eCSSProperty_mask:
     return ParseImageLayers(nsStyleImageLayers::kMaskLayerTable);
   case eCSSProperty_mask_repeat:
@@ -12018,7 +12017,6 @@ CSSParserImpl::ParsePropertyByFunction(nsCSSPropertyID aPropID)
                aPropID == eCSSProperty_mask_position_x);
   case eCSSProperty_mask_size:
     return ParseImageLayerSize(eCSSProperty_mask_size);
-#endif
   case eCSSProperty__webkit_text_stroke:
     return ParseWebkitTextStroke();
   case eCSSProperty_all:
@@ -12424,7 +12422,7 @@ CSSParserImpl::ParseImageLayersItem(
   aState.mImage->mValue.SetNoneValue();
   aState.mAttachment->mValue.SetIntValue(NS_STYLE_IMAGELAYER_ATTACHMENT_SCROLL,
                                          eCSSUnit_Enumerated);
-  aState.mClip->mValue.SetIntValue(NS_STYLE_IMAGELAYER_CLIP_BORDER,
+  aState.mClip->mValue.SetIntValue(StyleGeometryBox::Border,
                                    eCSSUnit_Enumerated);
 
   aState.mRepeat->mXValue.SetIntValue(NS_STYLE_IMAGELAYER_REPEAT_REPEAT,
@@ -12437,10 +12435,10 @@ CSSParserImpl::ParseImageLayersItem(
   aState.mPositionY->mValue.SetArrayValue(positionYArr, eCSSUnit_Array);
 
   if (eCSSProperty_mask == aTable[nsStyleImageLayers::shorthand]) {
-    aState.mOrigin->mValue.SetIntValue(NS_STYLE_IMAGELAYER_ORIGIN_BORDER,
+    aState.mOrigin->mValue.SetIntValue(StyleGeometryBox::Border,
                                        eCSSUnit_Enumerated);
   } else {
-    aState.mOrigin->mValue.SetIntValue(NS_STYLE_IMAGELAYER_ORIGIN_PADDING,
+    aState.mOrigin->mValue.SetIntValue(StyleGeometryBox::Padding,
                                        eCSSUnit_Enumerated);
   }
   positionXArr->Item(1).SetPercentValue(0.0f);
@@ -12462,6 +12460,8 @@ CSSParserImpl::ParseImageLayersItem(
        haveMode = false,
        haveSomething = false;
 
+  const KTableEntry* originTable =
+    nsCSSProps::kKeywordTableTable[aTable[nsStyleImageLayers::origin]];
   while (GetToken(true)) {
     nsCSSTokenType tt = mToken.mType;
     UngetToken(); // ...but we'll still cheat and use mToken
@@ -12531,8 +12531,7 @@ CSSParserImpl::ParseImageLayersItem(
           aState.mSize->mXValue = scratch.mXValue;
           aState.mSize->mYValue = scratch.mYValue;
         }
-      } else if (nsCSSProps::FindKeyword(keyword,
-                   nsCSSProps::kImageLayerOriginKTable, dummy)) {
+      } else if (nsCSSProps::FindKeyword(keyword, originTable, dummy)) {
         if (haveOrigin)
           return false;
         haveOrigin = true;
@@ -12547,23 +12546,15 @@ CSSParserImpl::ParseImageLayersItem(
         // immediately following the first one (for background-origin).
 
 #ifdef DEBUG
-        for (size_t i = 0; nsCSSProps::kImageLayerOriginKTable[i].mValue != -1; i++) {
+        const KTableEntry* clipTable =
+          nsCSSProps::kKeywordTableTable[aTable[nsStyleImageLayers::clip]];
+        for (size_t i = 0; originTable[i].mValue != -1; i++) {
           // For each keyword & value in kOriginKTable, ensure that
           // kBackgroundKTable has a matching entry at the same position.
-          MOZ_ASSERT(nsCSSProps::kImageLayerOriginKTable[i].mKeyword ==
-                     nsCSSProps::kBackgroundClipKTable[i].mKeyword);
-          MOZ_ASSERT(nsCSSProps::kImageLayerOriginKTable[i].mValue ==
-                     nsCSSProps::kBackgroundClipKTable[i].mValue);
+          MOZ_ASSERT(originTable[i].mKeyword == clipTable[i].mKeyword);
+          MOZ_ASSERT(originTable[i].mValue == clipTable[i].mValue);
         }
 #endif
-        static_assert(NS_STYLE_IMAGELAYER_CLIP_BORDER ==
-                      NS_STYLE_IMAGELAYER_ORIGIN_BORDER &&
-                      NS_STYLE_IMAGELAYER_CLIP_PADDING ==
-                      NS_STYLE_IMAGELAYER_ORIGIN_PADDING &&
-                      NS_STYLE_IMAGELAYER_CLIP_CONTENT ==
-                      NS_STYLE_IMAGELAYER_ORIGIN_CONTENT,
-                      "bg-clip and bg-origin style constants must agree");
-
         CSSParseResult result =
           ParseSingleValueProperty(aState.mClip->mValue,
                                    aTable[nsStyleImageLayers::clip]);
diff --git a/layout/style/nsCSSPropAliasList.h b/layout/style/nsCSSPropAliasList.h
index 2699549ffc..f7938af9ed 100644
--- a/layout/style/nsCSSPropAliasList.h
+++ b/layout/style/nsCSSPropAliasList.h
@@ -453,7 +453,6 @@ CSS_PROP_ALIAS(-webkit-user-select,
                WebkitUserSelect,
                WEBKIT_PREFIX_PREF)
 
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
 CSS_PROP_ALIAS(-webkit-mask,
                mask,
                WebkitMask,
@@ -494,5 +493,4 @@ CSS_PROP_ALIAS(-webkit-mask-size,
                mask_size,
                WebkitMaskSize,
                WEBKIT_PREFIX_PREF)
-#endif
 #undef WEBKIT_PREFIX_PREF
diff --git a/layout/style/nsCSSPropList.h b/layout/style/nsCSSPropList.h
index b04921dcb5..2049f70e88 100644
--- a/layout/style/nsCSSPropList.h
+++ b/layout/style/nsCSSPropList.h
@@ -564,7 +564,7 @@ CSS_PROP_BACKGROUND(
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
     "",
     VARIANT_KEYWORD, // used by list parsing
-    kImageLayerOriginKTable,
+    kBackgroundOriginKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_SHORTHAND(
@@ -2645,19 +2645,6 @@ CSS_PROP_SVG(
     nullptr,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
-#ifndef MOZ_ENABLE_MASK_AS_SHORTHAND
-CSS_PROP_SVGRESET(
-    mask,
-    mask,
-    Mask,
-    CSS_PROPERTY_PARSE_VALUE |
-      CSS_PROPERTY_CREATES_STACKING_CONTEXT,
-    "",
-    VARIANT_HUO,
-    nullptr,
-    CSS_PROP_NO_OFFSET,
-    eStyleAnimType_Discrete)
-#else
 CSS_PROP_SHORTHAND(
     mask,
     mask,
@@ -2672,7 +2659,7 @@ CSS_PROP_SVGRESET(
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
     "",
     VARIANT_KEYWORD, // used by list parsing
-    kImageLayerOriginKTable,
+    kMaskClipKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_SVGRESET(
@@ -2718,7 +2705,7 @@ CSS_PROP_SVGRESET(
         CSS_PROPERTY_VALUE_LIST_USES_COMMAS,
     "",
     VARIANT_KEYWORD, // used by list parsing
-    kImageLayerOriginKTable,
+    kMaskOriginKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Discrete)
 CSS_PROP_SHORTHAND(
@@ -2776,7 +2763,6 @@ CSS_PROP_SVGRESET(
     kImageLayerSizeKTable,
     CSS_PROP_NO_OFFSET,
     eStyleAnimType_Custom)
-#endif // MOZ_ENABLE_MASK_AS_SHORTHAND
 CSS_PROP_SVGRESET(
     mask-type,
     mask_type,
diff --git a/layout/style/nsCSSProps.cpp b/layout/style/nsCSSProps.cpp
index 9805eae14e..ac2978c277 100644
--- a/layout/style/nsCSSProps.cpp
+++ b/layout/style/nsCSSProps.cpp
@@ -932,33 +932,43 @@ const KTableEntry nsCSSProps::kImageLayerAttachmentKTable[] = {
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
-static_assert(NS_STYLE_IMAGELAYER_CLIP_BORDER == NS_STYLE_IMAGELAYER_ORIGIN_BORDER &&
-              NS_STYLE_IMAGELAYER_CLIP_PADDING == NS_STYLE_IMAGELAYER_ORIGIN_PADDING &&
-              NS_STYLE_IMAGELAYER_CLIP_CONTENT == NS_STYLE_IMAGELAYER_ORIGIN_CONTENT,
-              "Except background-clip:text, all {background,mask}-clip and "
-              "{background,mask}-origin style constants must agree");
-
-const KTableEntry nsCSSProps::kImageLayerOriginKTable[] = {
-  { eCSSKeyword_border_box, NS_STYLE_IMAGELAYER_ORIGIN_BORDER },
-  { eCSSKeyword_padding_box, NS_STYLE_IMAGELAYER_ORIGIN_PADDING },
-  { eCSSKeyword_content_box, NS_STYLE_IMAGELAYER_ORIGIN_CONTENT },
+const KTableEntry nsCSSProps::kBackgroundOriginKTable[] = {
+  { eCSSKeyword_border_box, StyleGeometryBox::Border },
+  { eCSSKeyword_padding_box, StyleGeometryBox::Padding },
+  { eCSSKeyword_content_box, StyleGeometryBox::Content },
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
 KTableEntry nsCSSProps::kBackgroundClipKTable[] = {
-  { eCSSKeyword_border_box, NS_STYLE_IMAGELAYER_CLIP_BORDER },
-  { eCSSKeyword_padding_box, NS_STYLE_IMAGELAYER_CLIP_PADDING },
-  { eCSSKeyword_content_box, NS_STYLE_IMAGELAYER_CLIP_CONTENT },
+  { eCSSKeyword_border_box, StyleGeometryBox::Border },
+  { eCSSKeyword_padding_box, StyleGeometryBox::Padding },
+  { eCSSKeyword_content_box, StyleGeometryBox::Content },
   // The next entry is controlled by the layout.css.background-clip-text.enabled
   // pref.
-  { eCSSKeyword_text, NS_STYLE_IMAGELAYER_CLIP_TEXT },
+  { eCSSKeyword_text, StyleGeometryBox::Text },
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
-static_assert(MOZ_ARRAY_LENGTH(nsCSSProps::kImageLayerOriginKTable) ==
-              MOZ_ARRAY_LENGTH(nsCSSProps::kBackgroundClipKTable) - 1,
-              "background-clip has one extra value, which is text, compared"
-              "to {background,mask}-origin");
+const KTableEntry nsCSSProps::kMaskOriginKTable[] = {
+  { eCSSKeyword_border_box, StyleGeometryBox::Border },
+  { eCSSKeyword_padding_box, StyleGeometryBox::Padding },
+  { eCSSKeyword_content_box, StyleGeometryBox::Content },
+  { eCSSKeyword_fill_box, StyleGeometryBox::Fill },
+  { eCSSKeyword_stroke_box, StyleGeometryBox::Stroke },
+  { eCSSKeyword_view_box, StyleGeometryBox::View },
+  { eCSSKeyword_UNKNOWN, -1 }
+};
+
+const KTableEntry nsCSSProps::kMaskClipKTable[] = {
+  { eCSSKeyword_border_box, StyleGeometryBox::Border },
+  { eCSSKeyword_padding_box, StyleGeometryBox::Padding },
+  { eCSSKeyword_content_box, StyleGeometryBox::Content },
+  { eCSSKeyword_fill_box, StyleGeometryBox::Fill },
+  { eCSSKeyword_stroke_box, StyleGeometryBox::Stroke },
+  { eCSSKeyword_view_box, StyleGeometryBox::View },
+  { eCSSKeyword_no_clip, StyleGeometryBox::NoClip },
+  { eCSSKeyword_UNKNOWN, -1 }
+};
 
 // Note: Don't change this table unless you update
 // ParseImageLayerPosition!
@@ -2346,13 +2356,13 @@ const KTableEntry nsCSSProps::kFillRuleKTable[] = {
 };
 
 const KTableEntry nsCSSProps::kClipPathGeometryBoxKTable[] = {
-  { eCSSKeyword_content_box, StyleClipPathGeometryBox::Content },
-  { eCSSKeyword_padding_box, StyleClipPathGeometryBox::Padding },
-  { eCSSKeyword_border_box, StyleClipPathGeometryBox::Border },
-  { eCSSKeyword_margin_box, StyleClipPathGeometryBox::Margin },
-  { eCSSKeyword_fill_box, StyleClipPathGeometryBox::Fill },
-  { eCSSKeyword_stroke_box, StyleClipPathGeometryBox::Stroke },
-  { eCSSKeyword_view_box, StyleClipPathGeometryBox::View },
+  { eCSSKeyword_content_box, StyleGeometryBox::Content },
+  { eCSSKeyword_padding_box, StyleGeometryBox::Padding },
+  { eCSSKeyword_border_box, StyleGeometryBox::Border },
+  { eCSSKeyword_margin_box, StyleGeometryBox::Margin },
+  { eCSSKeyword_fill_box, StyleGeometryBox::Fill },
+  { eCSSKeyword_stroke_box, StyleGeometryBox::Stroke },
+  { eCSSKeyword_view_box, StyleGeometryBox::View },
   { eCSSKeyword_UNKNOWN, -1 }
 };
 
@@ -3051,7 +3061,6 @@ static const nsCSSPropertyID gScrollSnapTypeSubpropTable[] = {
   eCSSProperty_scroll_snap_type_y,
   eCSSProperty_UNKNOWN
 };
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
 static const nsCSSPropertyID gMaskSubpropTable[] = {
   eCSSProperty_mask_image,
   eCSSProperty_mask_repeat,
@@ -3069,7 +3078,6 @@ static const nsCSSPropertyID gMaskPositionSubpropTable[] = {
   eCSSProperty_mask_position_y,
   eCSSProperty_UNKNOWN
 };
-#endif
 // FIXME: mask-border tables should be added when we implement
 // mask-border properties.
 
diff --git a/layout/style/nsCSSProps.h b/layout/style/nsCSSProps.h
index dfe35afd82..e67e1d41d1 100644
--- a/layout/style/nsCSSProps.h
+++ b/layout/style/nsCSSProps.h
@@ -717,6 +717,8 @@ public:
   static const KTableEntry kTransformStyleKTable[];
   static const KTableEntry kImageLayerAttachmentKTable[];
   static const KTableEntry kImageLayerOriginKTable[];
+  static const KTableEntry kBackgroundOriginKTable[];
+  static const KTableEntry kMaskOriginKTable[];
   static const KTableEntry kImageLayerPositionKTable[];
   static const KTableEntry kImageLayerRepeatKTable[];
   static const KTableEntry kImageLayerRepeatPartKTable[];
@@ -726,6 +728,7 @@ public:
   // Not const because we modify its entries when the pref
   // "layout.css.background-clip.text" changes:
   static KTableEntry kBackgroundClipKTable[];
+  static const KTableEntry kMaskClipKTable[];
   static const KTableEntry kBlendModeKTable[];
   static const KTableEntry kBorderCollapseKTable[];
   static const KTableEntry kBorderImageRepeatKTable[];
diff --git a/layout/style/nsComputedDOMStyle.cpp b/layout/style/nsComputedDOMStyle.cpp
index 4f8d3edf66..36c3a63857 100644
--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -74,6 +74,30 @@ NS_NewComputedDOMStyle(dom::Element* aElement, const nsAString& aPseudoElt,
   return computedStyle.forget();
 }
 
+static nsDOMCSSValueList*
+GetROCSSValueList(bool aCommaDelimited)
+{
+  return new nsDOMCSSValueList(aCommaDelimited, true);
+}
+
+template<typename T>
+already_AddRefed<CSSValue>
+GetBackgroundList(T nsStyleImageLayers::Layer::* aMember,
+                  uint32_t nsStyleImageLayers::* aCount,
+                  const nsStyleImageLayers& aLayers,
+                  const KTableEntry aTable[])
+{
+  RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(true);
+
+  for (uint32_t i = 0, i_end = aLayers.*aCount; i < i_end; ++i) {
+    RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
+    val->SetIdent(nsCSSProps::ValueToKeywordEnum(aLayers.mLayers[i].*aMember, aTable));
+    valueList->AppendCSSValue(val.forget());
+  }
+
+  return valueList.forget();
+}
+
 /**
  * An object that represents the ordered set of properties that are exposed on
  * an nsComputedDOMStyle object and how their computed values can be obtained.
@@ -1803,24 +1827,6 @@ nsComputedDOMStyle::DoGetFontVariantPosition()
 }
 
 already_AddRefed<CSSValue>
-nsComputedDOMStyle::GetBackgroundList(uint8_t nsStyleImageLayers::Layer::* aMember,
-                                      uint32_t nsStyleImageLayers::* aCount,
-                                      const nsStyleImageLayers& aLayers,
-                                      const KTableEntry aTable[])
-{
-  RefPtr<nsDOMCSSValueList> valueList = GetROCSSValueList(true);
-
-  for (uint32_t i = 0, i_end = aLayers.*aCount; i < i_end; ++i) {
-    RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
-    val->SetIdent(nsCSSProps::ValueToKeywordEnum(aLayers.mLayers[i].*aMember,
-                                                 aTable));
-    valueList->AppendCSSValue(val.forget());
-  }
-
-  return valueList.forget();
-}
-
-already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetBackgroundAttachment()
 {
   return GetBackgroundList(&nsStyleImageLayers::Layer::mAttachment,
@@ -2367,7 +2373,7 @@ nsComputedDOMStyle::DoGetBackgroundOrigin()
   return GetBackgroundList(&nsStyleImageLayers::Layer::mOrigin,
                            &nsStyleImageLayers::mOriginCount,
                            StyleBackground()->mImage,
-                           nsCSSProps::kImageLayerOriginKTable);
+                           nsCSSProps::kBackgroundOriginKTable);
 }
 
 void
@@ -5013,12 +5019,6 @@ nsComputedDOMStyle::DoGetTop()
   return GetOffsetWidthFor(NS_SIDE_TOP);
 }
 
-nsDOMCSSValueList*
-nsComputedDOMStyle::GetROCSSValueList(bool aCommaDelimited)
-{
-  return new nsDOMCSSValueList(aCommaDelimited, true);
-}
-
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::GetOffsetWidthFor(mozilla::css::Side aSide)
 {
@@ -6180,8 +6180,8 @@ nsComputedDOMStyle::DoGetMask()
   // need to support computed style for the cases where it used to be
   // a longhand.
   if (svg->mMask.mImageCount > 1 ||
-      firstLayer.mClip != NS_STYLE_IMAGELAYER_CLIP_BORDER ||
-      firstLayer.mOrigin != NS_STYLE_IMAGELAYER_ORIGIN_BORDER ||
+      firstLayer.mClip != StyleGeometryBox::Border ||
+      firstLayer.mOrigin != StyleGeometryBox::Border ||
       firstLayer.mComposite != NS_STYLE_MASK_COMPOSITE_ADD ||
       firstLayer.mMaskMode != NS_STYLE_MASK_MODE_MATCH_SOURCE ||
       !nsStyleImageLayers::IsInitialPositionForLayerType(
@@ -6200,14 +6200,13 @@ nsComputedDOMStyle::DoGetMask()
   return val.forget();
 }
 
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetMaskClip()
 {
   return GetBackgroundList(&nsStyleImageLayers::Layer::mClip,
                            &nsStyleImageLayers::mClipCount,
                            StyleSVGReset()->mMask,
-                           nsCSSProps::kImageLayerOriginKTable);
+                           nsCSSProps::kMaskClipKTable);
 }
 
 already_AddRefed<CSSValue>
@@ -6241,7 +6240,7 @@ nsComputedDOMStyle::DoGetMaskOrigin()
   return GetBackgroundList(&nsStyleImageLayers::Layer::mOrigin,
                            &nsStyleImageLayers::mOriginCount,
                            StyleSVGReset()->mMask,
-                           nsCSSProps::kImageLayerOriginKTable);
+                           nsCSSProps::kMaskOriginKTable);
 }
 
 already_AddRefed<CSSValue>
@@ -6278,7 +6277,6 @@ nsComputedDOMStyle::DoGetMaskSize()
   const nsStyleImageLayers& layers = StyleSVGReset()->mMask;
   return DoGetImageLayerSize(layers);
 }
-#endif
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetMaskType()
diff --git a/layout/style/nsComputedDOMStyle.h b/layout/style/nsComputedDOMStyle.h
index 27e2086e92..77df71ec89 100644
--- a/layout/style/nsComputedDOMStyle.h
+++ b/layout/style/nsComputedDOMStyle.h
@@ -53,6 +53,7 @@ private:
   // Convenience typedefs:
   typedef nsCSSProps::KTableEntry KTableEntry;
   typedef mozilla::dom::CSSValue CSSValue;
+  typedef mozilla::StyleGeometryBox StyleGeometryBox;
 
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
@@ -202,12 +203,6 @@ private:
                                                const nscolor& aDefaultColor,
                                                bool aIsBoxShadow);
 
-  already_AddRefed<CSSValue> GetBackgroundList(
-    uint8_t nsStyleImageLayers::Layer::* aMember,
-    uint32_t nsStyleImageLayers::* aCount,
-    const nsStyleImageLayers& aLayers,
-    const KTableEntry aTable[]);
-
   void GetCSSGradientString(const nsStyleGradient* aGradient,
                             nsAString& aString);
   void GetImageRectString(nsIURI* aURI,
@@ -310,7 +305,6 @@ private:
 
   /* Mask properties */
   already_AddRefed<CSSValue> DoGetMask();
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
   already_AddRefed<CSSValue> DoGetMaskImage();
   already_AddRefed<CSSValue> DoGetMaskPosition();
   already_AddRefed<CSSValue> DoGetMaskPositionX();
@@ -321,7 +315,7 @@ private:
   already_AddRefed<CSSValue> DoGetMaskSize();
   already_AddRefed<CSSValue> DoGetMaskMode();
   already_AddRefed<CSSValue> DoGetMaskComposite();
-#endif
+
   /* Padding properties */
   already_AddRefed<CSSValue> DoGetPaddingTop();
   already_AddRefed<CSSValue> DoGetPaddingBottom();
@@ -582,8 +576,6 @@ private:
   /* Custom properties */
   already_AddRefed<CSSValue> DoGetCustomProperty(const nsAString& aPropertyName);
 
-  nsDOMCSSValueList* GetROCSSValueList(bool aCommaDelimited);
-
   /* Helper functions */
   void SetToRGBAColor(nsROCSSPrimitiveValue* aValue, nscolor aColor);
   void SetValueFromComplexColor(nsROCSSPrimitiveValue* aValue,
diff --git a/layout/style/nsComputedDOMStylePropertyList.h b/layout/style/nsComputedDOMStylePropertyList.h
index 1983208acc..825976b583 100644
--- a/layout/style/nsComputedDOMStylePropertyList.h
+++ b/layout/style/nsComputedDOMStylePropertyList.h
@@ -332,7 +332,6 @@ COMPUTED_STYLE_PROP(marker_end,                    MarkerEnd)
 COMPUTED_STYLE_PROP(marker_mid,                    MarkerMid)
 COMPUTED_STYLE_PROP(marker_start,                  MarkerStart)
 COMPUTED_STYLE_PROP(mask,                          Mask)
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
 COMPUTED_STYLE_PROP(mask_clip,                     MaskClip)
 COMPUTED_STYLE_PROP(mask_composite,                MaskComposite)
 COMPUTED_STYLE_PROP(mask_image,                    MaskImage)
@@ -343,7 +342,6 @@ COMPUTED_STYLE_PROP(mask_position_x,               MaskPositionX)
 COMPUTED_STYLE_PROP(mask_position_y,               MaskPositionY)
 COMPUTED_STYLE_PROP(mask_repeat,                   MaskRepeat)
 COMPUTED_STYLE_PROP(mask_size,                     MaskSize)
-#endif
 COMPUTED_STYLE_PROP(mask_type,                     MaskType)
 COMPUTED_STYLE_PROP(paint_order,                   PaintOrder)
 COMPUTED_STYLE_PROP(shape_rendering,               ShapeRendering)
diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp
index 9b9fc3948e..6bcef02a05 100644
--- a/layout/style/nsRuleNode.cpp
+++ b/layout/style/nsRuleNode.cpp
@@ -22,6 +22,7 @@
 #include "mozilla/Unused.h"
 
 #include "mozilla/css/Declaration.h"
+#include "mozilla/TypeTraits.h"
 
 #include "nsAlgorithm.h" // for clamped()
 #include "nsRuleNode.h"
@@ -6800,6 +6801,21 @@ struct BackgroundItemComputer<nsCSSValueList, RefPtr<css::URLValueData>>
   }
 };
 
+template <typename T>
+struct BackgroundItemComputer<nsCSSValueList, T>
+{
+  typedef typename EnableIf<IsEnum<T>::value, T>::Type ComputedType;
+
+  static void ComputeValue(nsStyleContext* aStyleContext,
+                           const nsCSSValueList* aSpecifiedValue,
+                           ComputedType& aComputedValue,
+                           RuleNodeCacheConditions& aConditions)
+  {
+    aComputedValue =
+      static_cast<T>(aSpecifiedValue->mValue.GetIntValue());
+  }
+};
+
 /* Helper function for ComputePositionValue.
  * This function computes a single PositionCoord from two nsCSSValue objects,
  * which represent an edge and an offset from that edge.
@@ -7353,7 +7369,7 @@ nsRuleNode::ComputeBackgroundData(void* aStartStruct,
                     bg->mImage.mLayers,
                     parentBG->mImage.mLayers,
                     &nsStyleImageLayers::Layer::mClip,
-                    uint8_t(NS_STYLE_IMAGELAYER_CLIP_BORDER),
+                    StyleGeometryBox::Border,
                     parentBG->mImage.mClipCount,
                     bg->mImage.mClipCount, maxItemCount, rebuild, conditions);
 
@@ -7372,7 +7388,7 @@ nsRuleNode::ComputeBackgroundData(void* aStartStruct,
                     bg->mImage.mLayers,
                     parentBG->mImage.mLayers,
                     &nsStyleImageLayers::Layer::mOrigin,
-                    uint8_t(NS_STYLE_IMAGELAYER_ORIGIN_PADDING),
+                    StyleGeometryBox::Padding,
                     parentBG->mImage.mOriginCount,
                     bg->mImage.mOriginCount, maxItemCount, rebuild,
                     conditions);
@@ -10005,7 +10021,6 @@ nsRuleNode::ComputeSVGResetData(void* aStartStruct,
            parentSVGReset->mMaskType,
            NS_STYLE_MASK_TYPE_LUMINANCE);
 
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
   uint32_t maxItemCount = 1;
   bool rebuild = false;
 
@@ -10043,7 +10058,7 @@ nsRuleNode::ComputeSVGResetData(void* aStartStruct,
                     svgReset->mMask.mLayers,
                     parentSVGReset->mMask.mLayers,
                     &nsStyleImageLayers::Layer::mClip,
-                    uint8_t(NS_STYLE_IMAGELAYER_CLIP_BORDER),
+                    StyleGeometryBox::Border,
                     parentSVGReset->mMask.mClipCount,
                     svgReset->mMask.mClipCount, maxItemCount, rebuild,
                     conditions);
@@ -10053,7 +10068,7 @@ nsRuleNode::ComputeSVGResetData(void* aStartStruct,
                     svgReset->mMask.mLayers,
                     parentSVGReset->mMask.mLayers,
                     &nsStyleImageLayers::Layer::mOrigin,
-                    uint8_t(NS_STYLE_IMAGELAYER_ORIGIN_BORDER),
+                    StyleGeometryBox::Border,
                     parentSVGReset->mMask.mOriginCount,
                     svgReset->mMask.mOriginCount, maxItemCount, rebuild,
                     conditions);
@@ -10113,21 +10128,6 @@ nsRuleNode::ComputeSVGResetData(void* aStartStruct,
   if (rebuild) {
     FillAllBackgroundLists(svgReset->mMask, maxItemCount);
   }
-#else
-  // mask: none | <url>
-  const nsCSSValue* maskValue = aRuleData->ValueForMask();
-  if (eCSSUnit_URL == maskValue->GetUnit()) {
-    svgReset->mMask.mLayers[0].mSourceURI = maskValue->GetURLStructValue();
-  } else if (eCSSUnit_None == maskValue->GetUnit() ||
-             eCSSUnit_Initial == maskValue->GetUnit() ||
-             eCSSUnit_Unset == maskValue->GetUnit()) {
-    svgReset->mMask.mLayers[0].mSourceURI = nullptr;
-  } else if (eCSSUnit_Inherit == maskValue->GetUnit()) {
-    conditions.SetUncacheable();
-    svgReset->mMask.mLayers[0].mSourceURI =
-      parentSVGReset->mMask.mLayers[0].mSourceURI;
-  }
-#endif
 
   COMPUTE_END_RESET(SVGReset, svgReset)
 }
diff --git a/layout/style/nsStyleConsts.h b/layout/style/nsStyleConsts.h
index be588113e9..6d207aec9b 100644
--- a/layout/style/nsStyleConsts.h
+++ b/layout/style/nsStyleConsts.h
@@ -134,16 +134,35 @@ enum class StyleClear : uint8_t {
   Max = 13  // Max = (Both | Line)
 };
 
-// clip-path geometry box
-enum class StyleClipPathGeometryBox : uint8_t {
-  NoBox,
+// Define geometry box for clip-path's reference-box, background-clip,
+// background-origin, mask-clip and mask-origin.
+enum class StyleGeometryBox : uint8_t {
   Content,
   Padding,
   Border,
-  Margin,
-  Fill,
-  Stroke,
-  View,
+  Margin,  // XXX Bug 1260094 comment 9.
+           // Although margin-box is required by mask-origin and mask-clip, we
+           // do not implement that due to lack of support in other browsers.
+           // clip-path reference-box only.
+  Fill,    // mask-clip, mask-origin and clip-path reference-box only.
+  Stroke,  // mask-clip, mask-origin and clip-path reference-box only.
+  View,    // mask-clip, mask-origin and clip-path reference-box only.
+  NoClip,  // mask-clip only.
+  Text,    // background-clip only.
+  NoBox,   // Depending on which kind of element this style value applied on,
+           // the default value of a reference-box can be different.
+           // For an HTML element, the default value of reference-box is
+           // border-box; for an SVG element, the default value is fill-box.
+           // Since we can not determine the default value at parsing time,
+           // set it as NoBox so that we make a decision later.
+           // clip-path reference-box only.
+  MozAlmostPadding = 127 // A magic value that we use for our "pretend that
+                         // background-clip is 'padding' when we have a solid
+                         // border" optimization.  This isn't actually equal
+                         // to StyleGeometryBox::Padding because using that
+                         // causes antialiasing seams between the background
+                         // and border.
+                         // background-clip only.
 };
 
 // fill-rule
@@ -359,14 +378,6 @@ enum class FillMode : uint32_t;
 #define NS_STYLE_IMAGELAYER_ATTACHMENT_FIXED         1
 #define NS_STYLE_IMAGELAYER_ATTACHMENT_LOCAL         2
 
-// See nsStyleImageLayers
-// Code depends on these constants having the same values as IMAGELAYER_ORIGIN_*
-#define NS_STYLE_IMAGELAYER_CLIP_BORDER              0
-#define NS_STYLE_IMAGELAYER_CLIP_PADDING             1
-#define NS_STYLE_IMAGELAYER_CLIP_CONTENT             2
-// One extra constant which does not exist in IMAGELAYER_ORIGIN_*
-#define NS_STYLE_IMAGELAYER_CLIP_TEXT                3
-
 // A magic value that we use for our "pretend that background-clip is
 // 'padding' when we have a solid border" optimization.  This isn't
 // actually equal to NS_STYLE_IMAGELAYER_CLIP_PADDING because using that
@@ -375,12 +386,6 @@ enum class FillMode : uint32_t;
 #define NS_STYLE_IMAGELAYER_CLIP_MOZ_ALMOST_PADDING  127
 
 // See nsStyleImageLayers
-// Code depends on these constants having the same values as BG_CLIP_*
-#define NS_STYLE_IMAGELAYER_ORIGIN_BORDER            0
-#define NS_STYLE_IMAGELAYER_ORIGIN_PADDING           1
-#define NS_STYLE_IMAGELAYER_ORIGIN_CONTENT           2
-
-// See nsStyleImageLayers
 // The parser code depends on |ing these values together.
 #define NS_STYLE_IMAGELAYER_POSITION_CENTER          (1<<0)
 #define NS_STYLE_IMAGELAYER_POSITION_TOP             (1<<1)
diff --git a/layout/style/nsStyleStruct.cpp b/layout/style/nsStyleStruct.cpp
index 52491a288a..72c1037243 100644
--- a/layout/style/nsStyleStruct.cpp
+++ b/layout/style/nsStyleStruct.cpp
@@ -2465,7 +2465,6 @@ const nsCSSPropertyID nsStyleImageLayers::kBackgroundLayerTable[] = {
   eCSSProperty_UNKNOWN                    // composite
 };
 
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
 const nsCSSPropertyID nsStyleImageLayers::kMaskLayerTable[] = {
   eCSSProperty_mask,                      // shorthand
   eCSSProperty_UNKNOWN,                   // color
@@ -2480,7 +2479,6 @@ const nsCSSPropertyID nsStyleImageLayers::kMaskLayerTable[] = {
   eCSSProperty_mask_mode,                 // maskMode
   eCSSProperty_mask_composite             // composite
 };
-#endif
 
 nsStyleImageLayers::nsStyleImageLayers(nsStyleImageLayers::LayerType aType)
   : mAttachmentCount(1)
@@ -2787,7 +2785,7 @@ nsStyleImageLayers::Size::operator==(const Size& aOther) const
 }
 
 nsStyleImageLayers::Layer::Layer()
-  : mClip(NS_STYLE_IMAGELAYER_CLIP_BORDER)
+  : mClip(StyleGeometryBox::Border)
   , mAttachment(NS_STYLE_IMAGELAYER_ATTACHMENT_SCROLL)
   , mBlendMode(NS_STYLE_BLEND_NORMAL)
   , mComposite(NS_STYLE_MASK_COMPOSITE_ADD)
@@ -2809,10 +2807,10 @@ nsStyleImageLayers::Layer::Initialize(nsStyleImageLayers::LayerType aType)
   mPosition.SetInitialPercentValues(0.0f);
 
   if (aType == LayerType::Background) {
-    mOrigin = NS_STYLE_IMAGELAYER_ORIGIN_PADDING;
+    mOrigin = StyleGeometryBox::Padding;
   } else {
     MOZ_ASSERT(aType == LayerType::Mask, "unsupported layer type.");
-    mOrigin = NS_STYLE_IMAGELAYER_ORIGIN_BORDER;
+    mOrigin = StyleGeometryBox::Border;
   }
 }
 
diff --git a/layout/style/nsStyleStruct.h b/layout/style/nsStyleStruct.h
index 1cadea8406..c8182b8f14 100644
--- a/layout/style/nsStyleStruct.h
+++ b/layout/style/nsStyleStruct.h
@@ -782,6 +782,8 @@ struct nsStyleImageLayers {
   struct Layer;
   friend struct Layer;
   struct Layer {
+    typedef mozilla::StyleGeometryBox StyleGeometryBox;
+
     nsStyleImage  mImage;         // [reset]
     RefPtr<mozilla::css::URLValueData> mSourceURI;  // [reset]
                                   // mask-only property
@@ -793,9 +795,9 @@ struct nsStyleImageLayers {
                                   // or an ImageValue.)
     mozilla::Position mPosition;  // [reset]
     Size          mSize;          // [reset]
-    uint8_t       mClip;          // [reset] See nsStyleConsts.h
+    StyleGeometryBox  mClip;      // [reset] See nsStyleConsts.h
     MOZ_INIT_OUTSIDE_CTOR
-      uint8_t     mOrigin;        // [reset] See nsStyleConsts.h
+      StyleGeometryBox mOrigin;   // [reset] See nsStyleConsts.h
     uint8_t       mAttachment;    // [reset] See nsStyleConsts.h
                                   // background-only property
                                   // This property is used for background layer
@@ -2755,7 +2757,7 @@ private:
   ReferenceBox mReferenceBox = ReferenceBox::NoBox;
 };
 
-using StyleClipPath = StyleShapeSource<StyleClipPathGeometryBox>;
+using StyleClipPath = StyleShapeSource<StyleGeometryBox>;
 using StyleShapeOutside = StyleShapeSource<StyleShapeOutsideShapeBox>;
 
 } // namespace mozilla
diff --git a/layout/svg/nsCSSClipPathInstance.cpp b/layout/svg/nsCSSClipPathInstance.cpp
index 828b10eaca..01f7de248e 100644
--- a/layout/svg/nsCSSClipPathInstance.cpp
+++ b/layout/svg/nsCSSClipPathInstance.cpp
@@ -62,122 +62,12 @@ nsCSSClipPathInstance::HitTestBasicShapeClip(nsIFrame* aFrame,
   return path->ContainsPoint(ToPoint(aPoint) * pixelRatio, Matrix());
 }
 
-nsRect
-nsCSSClipPathInstance::ComputeSVGReferenceRect()
-{
-  MOZ_ASSERT(mTargetFrame->GetContent()->IsSVGElement());
-  nsRect r;
-
-  // For SVG elements without associated CSS layout box, the used value for
-  // content-box, padding-box, border-box and margin-box is fill-box.
-  switch (mClipPathStyle.GetReferenceBox()) {
-    case StyleClipPathGeometryBox::Stroke: {
-      // XXX Bug 1299876
-      // The size of srtoke-box is not correct if this graphic element has
-      // specific stroke-linejoin or stroke-linecap.
-      gfxRect bbox = nsSVGUtils::GetBBox(mTargetFrame,
-                nsSVGUtils::eBBoxIncludeFill | nsSVGUtils::eBBoxIncludeStroke);
-      r = nsLayoutUtils::RoundGfxRectToAppRect(bbox,
-                                         nsPresContext::AppUnitsPerCSSPixel());
-      break;
-    }
-    case StyleClipPathGeometryBox::View: {
-      nsIContent* content = mTargetFrame->GetContent();
-      nsSVGElement* element = static_cast<nsSVGElement*>(content);
-      SVGSVGElement* svgElement = element->GetCtx();
-      MOZ_ASSERT(svgElement);
-
-      if (svgElement && svgElement->HasViewBoxRect()) {
-        // If a ‘viewBox‘ attribute is specified for the SVG viewport creating
-        // element:
-        // 1. The reference box is positioned at the origin of the coordinate
-        //    system established by the ‘viewBox‘ attribute.
-        // 2. The dimension of the reference box is set to the width and height
-        //    values of the ‘viewBox‘ attribute.
-        nsSVGViewBox* viewBox = svgElement->GetViewBox();
-        const nsSVGViewBoxRect& value = viewBox->GetAnimValue();
-        r = nsRect(nsPresContext::CSSPixelsToAppUnits(value.x),
-                   nsPresContext::CSSPixelsToAppUnits(value.y),
-                   nsPresContext::CSSPixelsToAppUnits(value.width),
-                   nsPresContext::CSSPixelsToAppUnits(value.height));
-      } else {
-        // No viewBox is specified, uses the nearest SVG viewport as reference
-        // box.
-        svgFloatSize viewportSize = svgElement->GetViewportSize();
-        r = nsRect(0, 0,
-                   nsPresContext::CSSPixelsToAppUnits(viewportSize.width),
-                   nsPresContext::CSSPixelsToAppUnits(viewportSize.height));
-      }
-
-      break;
-    }
-    case StyleClipPathGeometryBox::NoBox:
-    case StyleClipPathGeometryBox::Border:
-    case StyleClipPathGeometryBox::Content:
-    case StyleClipPathGeometryBox::Padding:
-    case StyleClipPathGeometryBox::Margin:
-    case StyleClipPathGeometryBox::Fill: {
-      gfxRect bbox = nsSVGUtils::GetBBox(mTargetFrame,
-                                         nsSVGUtils::eBBoxIncludeFill);
-      r = nsLayoutUtils::RoundGfxRectToAppRect(bbox,
-                                         nsPresContext::AppUnitsPerCSSPixel());
-      break;
-    }
-    default:{
-      MOZ_ASSERT_UNREACHABLE("unknown StyleClipPathGeometryBox type");
-      gfxRect bbox = nsSVGUtils::GetBBox(mTargetFrame,
-                                         nsSVGUtils::eBBoxIncludeFill);
-      r = nsLayoutUtils::RoundGfxRectToAppRect(bbox,
-                                         nsPresContext::AppUnitsPerCSSPixel());
-      break;
-    }
-  }
-
-  return r;
-}
-
-nsRect
-nsCSSClipPathInstance::ComputeHTMLReferenceRect()
-{
-  nsRect r;
-
-  // For elements with associated CSS layout box, the used value for fill-box,
-  // stroke-box and view-box is border-box.
-  switch (mClipPathStyle.GetReferenceBox()) {
-    case StyleClipPathGeometryBox::Content:
-      r = mTargetFrame->GetContentRectRelativeToSelf();
-      break;
-    case StyleClipPathGeometryBox::Padding:
-      r = mTargetFrame->GetPaddingRectRelativeToSelf();
-      break;
-    case StyleClipPathGeometryBox::Margin:
-      r = mTargetFrame->GetMarginRectRelativeToSelf();
-      break;
-    case StyleClipPathGeometryBox::NoBox:
-    case StyleClipPathGeometryBox::Border:
-    case StyleClipPathGeometryBox::Fill:
-    case StyleClipPathGeometryBox::Stroke:
-    case StyleClipPathGeometryBox::View:
-      r = mTargetFrame->GetRectRelativeToSelf();
-      break;
-    default:
-      MOZ_ASSERT_UNREACHABLE("unknown StyleClipPathGeometryBox type");
-      r = mTargetFrame->GetRectRelativeToSelf();
-      break;
-  }
-
-  return r;
-}
-
 already_AddRefed<Path>
 nsCSSClipPathInstance::CreateClipPath(DrawTarget* aDrawTarget)
 {
-  // We use ComputeSVGReferenceRect for all SVG elements, except <svg>
-  // element, which does have an associated CSS layout box. In this case we
-  // should still use ComputeHTMLReferenceRect for region computing.
-  nsRect r = mTargetFrame->IsFrameOfType(nsIFrame::eSVG) &&
-             (mTargetFrame->GetType() != nsGkAtoms::svgOuterSVGFrame)
-             ? ComputeSVGReferenceRect() : ComputeHTMLReferenceRect();
+  nsRect r =
+    nsLayoutUtils::ComputeGeometryBox(mTargetFrame,
+                                      mClipPathStyle.GetReferenceBox());
 
   if (mClipPathStyle.GetType() != StyleShapeSourceType::Shape) {
     // TODO Clip to border-radius/reference box if no shape
diff --git a/layout/svg/nsCSSClipPathInstance.h b/layout/svg/nsCSSClipPathInstance.h
index 3b0724dbd0..33d92e738e 100644
--- a/layout/svg/nsCSSClipPathInstance.h
+++ b/layout/svg/nsCSSClipPathInstance.h
@@ -48,10 +48,6 @@ private:
   already_AddRefed<Path> CreateClipPathInset(DrawTarget* aDrawTarget,
                                              const nsRect& aRefBox);
 
-
-  nsRect ComputeHTMLReferenceRect();
-  nsRect ComputeSVGReferenceRect();
-
   /**
    * The frame for the element that is currently being clipped.
    */
diff --git a/layout/svg/nsSVGIntegrationUtils.cpp b/layout/svg/nsSVGIntegrationUtils.cpp
index 498f693937..0003e1a73e 100644
--- a/layout/svg/nsSVGIntegrationUtils.cpp
+++ b/layout/svg/nsSVGIntegrationUtils.cpp
@@ -509,71 +509,108 @@ PaintMaskSurface(const PaintFramesParams& aParams,
   return DrawResult::SUCCESS;
 }
 
-static DrawResult
+struct MaskPaintResult {
+  RefPtr<SourceSurface> maskSurface;
+  Matrix maskTransform;
+  DrawResult result;
+  bool transparentBlackMask;
+  bool opacityApplied;
+
+ MaskPaintResult()
+    : result(DrawResult::SUCCESS), transparentBlackMask(false),
+      opacityApplied(false)
+  {}
+};
+
+static MaskPaintResult
 CreateAndPaintMaskSurface(const PaintFramesParams& aParams,
                           float aOpacity, nsStyleContext* aSC,
                           const nsTArray<nsSVGMaskFrame*>& aMaskFrames,
-                          const nsPoint& aOffsetToUserSpace,
-                          Matrix& aOutMaskTransform,
-                          RefPtr<SourceSurface>& aOutMaskSurface,
-                          bool& aOpacityApplied)
+                          const nsPoint& aOffsetToUserSpace)
 {
   const nsStyleSVGReset *svgReset = aSC->StyleSVGReset();
   MOZ_ASSERT(aMaskFrames.Length() > 0);
+  MaskPaintResult paintResult;
 
   gfxContext& ctx = aParams.ctx;
 
-  // There is only one SVG mask.
+  // Optimization for single SVG mask.
   if (((aMaskFrames.Length() == 1) && aMaskFrames[0])) {
     gfxMatrix cssPxToDevPxMatrix =
     nsSVGIntegrationUtils::GetCSSPxToDevPxMatrix(aParams.frame);
+    paintResult.opacityApplied = true;
 
-    aOpacityApplied = true;
-    aOutMaskSurface =
+    paintResult.maskSurface =
       aMaskFrames[0]->GetMaskForMaskedFrame(&ctx, aParams.frame,
                                             cssPxToDevPxMatrix, aOpacity,
-                                            &aOutMaskTransform,
+                                            &paintResult.maskTransform,
                                             svgReset->mMask.mLayers[0].mMaskMode);
-    return DrawResult::SUCCESS;
+    if (!paintResult.maskSurface) {
+      paintResult.transparentBlackMask = true;
+    }
+
+    return paintResult;
   }
 
   const IntRect& maskSurfaceRect = aParams.maskRect;
   if (maskSurfaceRect.IsEmpty()) {
-    return DrawResult::SUCCESS;
+    paintResult.transparentBlackMask = true;
+    return paintResult;
   }
 
   RefPtr<DrawTarget> maskDT =
       ctx.GetDrawTarget()->CreateSimilarDrawTarget(maskSurfaceRect.Size(),
                                                    SurfaceFormat::A8);
   if (!maskDT || !maskDT->IsValid()) {
-    return DrawResult::TEMPORARY_ERROR;
+    paintResult.result = DrawResult::TEMPORARY_ERROR;
+    return paintResult;
   }
 
   // Set aAppliedOpacity as true only if all mask layers are svg mask.
   // In this case, we will apply opacity into the final mask surface, so the
   // caller does not need to apply it again.
-  aOpacityApplied = !HasNonSVGMask(aMaskFrames);
+  paintResult.opacityApplied = !HasNonSVGMask(aMaskFrames);
 
   // Set context's matrix on maskContext, offset by the maskSurfaceRect's
   // position. This makes sure that we combine the masks in device space.
   gfxMatrix maskSurfaceMatrix =
     ctx.CurrentMatrix() * gfxMatrix::Translation(-aParams.maskRect.TopLeft());
 
-  DrawResult result = PaintMaskSurface(aParams, maskDT,
-                                       aOpacityApplied ? aOpacity : 1.0,
-                                       aSC, aMaskFrames, maskSurfaceMatrix,
-                                       aOffsetToUserSpace);
-  if (result != DrawResult::SUCCESS) {
-    return result;
-  }
-
-  aOutMaskTransform = ToMatrix(maskSurfaceMatrix);
-  if (!aOutMaskTransform.Invert()) {
-    return DrawResult::SUCCESS;
+  paintResult.result = PaintMaskSurface(aParams, maskDT,
+                                        paintResult.opacityApplied
+                                          ? aOpacity : 1.0,
+                                        aSC, aMaskFrames, maskSurfaceMatrix,
+                                        aOffsetToUserSpace);
+  if (paintResult.result != DrawResult::SUCCESS) {
+    // Now we know the status of mask resource since we used it while painting.
+    // According to the return value of PaintMaskSurface, we know whether mask
+    // resource is resolvable or not.
+    //
+    // For a HTML doc:
+    //   According to css-masking spec, always create a mask surface when
+    //   we have any item in maskFrame even if all of those items are
+    //   non-resolvable <mask-sources> or <images>.
+    //   Set paintResult.transparentBlackMask as true,  the caller should stop
+    //   painting masked content as if this mask is a transparent black one.
+    // For a SVG doc:
+    //   SVG 1.1 say that if we fail to resolve a mask, we should draw the
+    //   object unmasked.
+    //   Left patinResult.maskSurface empty, the caller should paint all
+    //   masked content as if this mask is an opaque white one(no mask).
+    paintResult.transparentBlackMask =
+      !(aParams.frame->GetStateBits() & NS_FRAME_SVG_LAYOUT);
+
+    MOZ_ASSERT(!paintResult.maskSurface);
+    return paintResult;
+ }
+
+  paintResult.maskTransform = ToMatrix(maskSurfaceMatrix);
+  if (!paintResult.maskTransform.Invert()) {
+    return paintResult;
   }
 
-  aOutMaskSurface = maskDT->Snapshot();
-  return DrawResult::SUCCESS;
+  paintResult.maskSurface = maskDT->Snapshot();
+  return paintResult;
 }
 
 static bool
@@ -783,6 +820,8 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
                              maskUsage.shouldGenerateClipMaskLayer ||
                              maskUsage.shouldGenerateMaskLayer);
 
+  bool shouldPushMask = false;
+
   /* Check if we need to do additional operations on this child's
    * rendering, which necessitates rendering into another surface. */
   if (shouldGenerateMask) {
@@ -800,14 +839,23 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
       // instead of the first continuation frame.
       SetupContextMatrix(frame, aParams, offsetToBoundingBox,
                          offsetToUserSpace);
-      result = CreateAndPaintMaskSurface(aParams, maskUsage.opacity,
-                                         firstFrame->StyleContext(),
-                                         maskFrames, offsetToUserSpace,
-                                         maskTransform, maskSurface,
-                                         opacityApplied);
-      if (!maskSurface) {
-        // Entire surface is clipped out.
-        return result;
+      MaskPaintResult paintResult =
+        CreateAndPaintMaskSurface(aParams, maskUsage.opacity,
+                                  firstFrame->StyleContext(),
+                                  maskFrames, offsetToUserSpace);
+
+      if (paintResult.transparentBlackMask) {
+        MOZ_ASSERT(paintResult.result != DrawResult::SUCCESS);
+        return paintResult.result;
+      }
+
+      result &= paintResult.result;
+      maskSurface = paintResult.maskSurface;
+      if (maskSurface) {
+        MOZ_ASSERT(paintResult.result == DrawResult::SUCCESS);
+        shouldPushMask = true;
+        maskTransform = paintResult.maskTransform;
+        opacityApplied = paintResult.opacityApplied;
       }
     }
 
@@ -831,6 +879,8 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
         // failure in nsSVGClipPathFrame::GetClipMask.
         return result;
       }
+
+      shouldPushMask = true;
     }
 
     // opacity != 1.0f.
@@ -841,18 +891,22 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
       matSR.SetContext(&context);
       SetupContextMatrix(firstFrame, aParams, offsetToBoundingBox,
                          offsetToUserSpace);
+      shouldPushMask = true;
     }
 
-    if (aParams.layerManager->GetRoot()->GetContentFlags() & Layer::CONTENT_COMPONENT_ALPHA) {
-      context.PushGroupAndCopyBackground(gfxContentType::COLOR_ALPHA,
-                                         opacityApplied
-                                           ? 1.0
-                                           : maskUsage.opacity,
-                                         maskSurface, maskTransform);
-    } else {
-      context.PushGroupForBlendBack(gfxContentType::COLOR_ALPHA,
-                                    opacityApplied ? 1.0 : maskUsage.opacity,
-                                    maskSurface, maskTransform);
+    if (shouldPushMask) {
+      if (aParams.layerManager->GetRoot()->GetContentFlags() &
+          Layer::CONTENT_COMPONENT_ALPHA) {
+        context.PushGroupAndCopyBackground(gfxContentType::COLOR_ALPHA,
+                                           opacityApplied
+                                             ? 1.0
+                                             : maskUsage.opacity,
+                                           maskSurface, maskTransform);
+      } else {
+        context.PushGroupForBlendBack(gfxContentType::COLOR_ALPHA,
+                                      opacityApplied ? 1.0 : maskUsage.opacity,
+                                      maskSurface, maskTransform);
+      }
     }
   }
 
@@ -899,7 +953,7 @@ nsSVGIntegrationUtils::PaintMaskAndClipPath(const PaintFramesParams& aParams)
     context.PopClip();
   }
 
-  if (shouldGenerateMask) {
+  if (shouldPushMask) {
     context.PopGroupAndBlend();
   }
 
diff --git a/layout/svg/nsSVGUtils.cpp b/layout/svg/nsSVGUtils.cpp
index 344ebf645a..0bded21ffe 100644
--- a/layout/svg/nsSVGUtils.cpp
+++ b/layout/svg/nsSVGUtils.cpp
@@ -514,26 +514,7 @@ nsSVGUtils::DetermineMaskUsage(nsIFrame* aFrame, bool aHandleOpacity,
 
   nsTArray<nsSVGMaskFrame*> maskFrames = effectProperties.GetMaskFrames();
 
-#ifdef MOZ_ENABLE_MASK_AS_SHORTHAND
-  // For a HTML doc:
-  //   According to css-masking spec, always create a mask surface when we
-  //   have any item in maskFrame even if all of those items are
-  //   non-resolvable <mask-sources> or <images>, we still need to create a
-  //   transparent black mask layer under this condition.
-  // For a SVG doc:
-  //   SVG 1.1 say that  if we fail to resolve a mask, we should draw the
-  //   object unmasked.
-  aUsage.shouldGenerateMaskLayer =
-    (aFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT)
-      ? maskFrames.Length() == 1 && maskFrames[0]
-      : maskFrames.Length() > 0;
-#else
-  // Since we do not support image mask so far, we should treat any
-  // unresolvable mask as no mask. Otherwise, any object with a valid image
-  // mask, e.g. url("xxx.png"), will become invisible just because we can not
-  // handle image mask correctly. (See bug 1294171)
-  aUsage.shouldGenerateMaskLayer = maskFrames.Length() == 1 && maskFrames[0];
-#endif
+  aUsage.shouldGenerateMaskLayer = (maskFrames.Length() > 0);
 
   bool isOK = effectProperties.HasNoFilterOrHasValidFilter();
   nsSVGClipPathFrame *clipPathFrame = effectProperties.GetClipPathFrame(&isOK);