[Blending and compositing] Implement the isolation CSS property in software

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index a4b7d13e5d2836afeccba621e21ca5d50954815d..9259a28555ad1bbd5100b5986b93061e4ef71ac8 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -2951,6 +2951,11 @@ bool RenderObject::hasBlendMode() const
     return RuntimeEnabledFeatures::cssCompositingEnabled() && style() && style()->hasBlendMode();
 }
 
+bool RenderObject::hasIsolation() const
+{
+    return RuntimeEnabledFeatures::cssCompositingEnabled() && style() && style()->hasIsolation();
+}
+
 static Color decorationColor(const RenderObject* object, RenderStyle* style)
 {
     Color result;