[SPv2] Add CSS mask support

third_party/WebKit/Source/core/paint/BoxPainter.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/BoxPainter.h"
 
 #include "core/HTMLNames.h"
 #include "core/frame/Settings.h"
 #include "core/html/HTMLFrameOwnerElement.h"
 #include "core/layout/ImageQualityController.h"
@@ skipping 800 matching lines @@
   LayoutObjectDrawingRecorder recorder(paintInfo.context, m_layoutBox,
                                        paintInfo.phase, visualOverflowRect);
   LayoutRect paintRect = LayoutRect(paintOffset, m_layoutBox.size());
   paintMaskImages(paintInfo, paintRect);
 }
 
 void BoxPainter::paintMaskImages(const PaintInfo& paintInfo,
                                  const LayoutRect& paintRect) {
   // Figure out if we need to push a transparency layer to render our mask.
   bool pushTransparencyLayer = false;
-  bool compositedMask =
-      m_layoutBox.hasLayer() && m_layoutBox.layer()->hasCompositedMask();
   bool flattenCompositingLayers =
       paintInfo.getGlobalPaintFlags() & GlobalPaintFlattenCompositingLayers;
+  bool maskBlendingAppliedByCompositor =
+      !flattenCompositingLayers && m_layoutBox.hasLayer() &&
+      m_layoutBox.layer()->maskBlendingAppliedByCompositor();
 
   bool allMaskImagesLoaded = true;
 
-  if (!compositedMask || flattenCompositingLayers) {
+  if (!maskBlendingAppliedByCompositor) {
     pushTransparencyLayer = true;
     StyleImage* maskBoxImage = m_layoutBox.style()->maskBoxImage().image();
     const FillLayer& maskLayers = m_layoutBox.style()->maskLayers();
 
     // Don't render a masked element until all the mask images have loaded, to
     // prevent a flash of unmasked content.
     if (maskBoxImage)
       allMaskImagesLoaded &= maskBoxImage->isLoaded();
 
     allMaskImagesLoaded &= maskLayers.imagesAreLoaded();
@@ skipping 252 matching lines @@
 bool BoxPainter::shouldForceWhiteBackgroundForPrintEconomy(
     const ComputedStyle& style,
     const Document& document) {
   return document.printing() &&
          style.printColorAdjust() == EPrintColorAdjust::kEconomy &&
          (!document.settings() ||
           !document.settings()->getShouldPrintBackgrounds());
 }
 
 }  // namespace blink