1 files changed, 25 insertions, 0 deletions
diff --git a/src/3rdparty/webkit/WebCore/platform/graphics/GraphicsLayer.cpp b/src/3rdparty/webkit/WebCore/platform/graphics/GraphicsLayer.cpp
index 2b85bfa30..b1825481e 100644
--- a/src/3rdparty/webkit/WebCore/platform/graphics/GraphicsLayer.cpp
+++ b/src/3rdparty/webkit/WebCore/platform/graphics/GraphicsLayer.cpp
@@ -449,6 +449,31 @@ void GraphicsLayer::setZPosition(float position)
 }
 #endif
 
+float GraphicsLayer::accumulatedOpacity() const
+{
+    if (!preserves3D())
+        return 1;
+        
+    return m_opacity * (parent() ? parent()->accumulatedOpacity() : 1);
+}
+
+void GraphicsLayer::distributeOpacity(float accumulatedOpacity)
+{
+    // If this is a transform layer we need to distribute our opacity to all our children
+    
+    // Incoming accumulatedOpacity is the contribution from our parent(s). We mutiply this by our own
+    // opacity to get the total contribution
+    accumulatedOpacity *= m_opacity;
+    
+    setOpacityInternal(accumulatedOpacity);
+    
+    if (preserves3D()) {
+        size_t numChildren = children().size();
+        for (size_t i = 0; i < numChildren; ++i)
+            children()[i]->distributeOpacity(accumulatedOpacity);
+    }
+}
+
 static void writeIndent(TextStream& ts, int indent)
 {
     for (int i = 0; i != indent; ++i)