mix-blend-mode implementation for accelerated layers - blink part

Source/core/rendering/RenderLayer.cpp

Index: Source/core/rendering/RenderLayer.cpp
diff --git a/Source/core/rendering/RenderLayer.cpp b/Source/core/rendering/RenderLayer.cpp
index ce1b55467411bbc81f6aa8ac81e3eafc3f8d2f27..ef30b52f2848672143c4ffab5fe52354e9feb3ab 100644
--- a/Source/core/rendering/RenderLayer.cpp
+++ b/Source/core/rendering/RenderLayer.cpp
@@ -3901,6 +3901,15 @@ inline bool RenderLayer::needsCompositingLayersRebuiltForFilters(const RenderSty
     return false;
 }
 
+inline bool RenderLayer::needsCompositingLayersRebuiltForBlending(const RenderStyle* oldStyle, const RenderStyle* newStyle) const
+{
+    ASSERT(newStyle);
+    if (!hasCompositedLayerMapping())
+        return false;
+    return (shouldIsolateCompositedDescendants() && !stackingNode()->isStackingContext())
+        || (oldStyle && (oldStyle->hasBlendMode() != newStyle->hasBlendMode()));
+}
+
 void RenderLayer::updateFilters(const RenderStyle* oldStyle, const RenderStyle* newStyle)
 {
     if (!hasOrHadFilters(oldStyle, newStyle))
@@ -3947,7 +3956,8 @@ void RenderLayer::styleChanged(StyleDifference, const RenderStyle* oldStyle)
     if (compositor()->updateLayerCompositingState(this)
         || needsCompositingLayersRebuiltForClip(oldStyle, newStyle)
         || needsCompositingLayersRebuiltForOverflow(oldStyle, newStyle)
-        || needsCompositingLayersRebuiltForFilters(oldStyle, newStyle, didPaintWithFilters))
+        || needsCompositingLayersRebuiltForFilters(oldStyle, newStyle, didPaintWithFilters)
+        || needsCompositingLayersRebuiltForBlending(oldStyle, newStyle))

[rosca, 2013/11/25 21:11:41]

I added this new check. The tree must be rebuilt if blending is turned on/off or
if the isolating stacking context doesn't need to be stacking context any
longer.
Added a new LayoutTest for this as well.

         compositor()->setCompositingLayersNeedRebuild();
     else if (hasCompositedLayerMapping())
         compositedLayerMapping()->updateGraphicsLayerGeometry();