Document reflection

third_party/WebKit/Source/core/paint/ReplicaPainter.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 "config.h"
 #include "core/paint/ReplicaPainter.h"
 
 #include "core/layout/LayoutReplica.h"
 #include "core/paint/LayoutObjectDrawingRecorder.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/PaintLayer.h"
 #include "core/paint/PaintLayerPainter.h"
 
 namespace blink {
 
 void ReplicaPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
+    // PaintLayerReflectionInfo should have set a transform on the LayoutReplica.
+    // Without it, we won't paint the reflection correctly.
+    ASSERT(m_layoutReplica.layer()->transform());
+
     if (paintInfo.phase != PaintPhaseForeground && paintInfo.phase != PaintPhaseMask)
         return;
 
     LayoutPoint adjustedPaintOffset = paintOffset + m_layoutReplica.location();
 
     if (paintInfo.phase == PaintPhaseForeground) {
         // Turn around and paint the parent layer. Use temporary clipRects, so that the layer doesn't end up caching clip rects
         // computing using the wrong rootLayer
-        PaintLayer* rootPaintingLayer = m_layoutReplica.layer()->transform() ? m_layoutReplica.layer()->parent() : m_layoutReplica.layer()->enclosingTransformedAncestor();
+        PaintLayer* rootPaintingLayer = m_layoutReplica.layer()->parent();
         PaintLayerPaintingInfo paintingInfo(rootPaintingLayer, LayoutRect(paintInfo.rect), GlobalPaintNormalPhase, LayoutSize(), 0);
         PaintLayerFlags flags = PaintLayerHaveTransparency | PaintLayerAppliedTransform | PaintLayerUncachedClipRects | PaintLayerPaintingReflection;
         PaintLayerPainter(*m_layoutReplica.layer()->parent()).paintLayer(paintInfo.context, paintingInfo, flags);
     } else if (paintInfo.phase == PaintPhaseMask) {
         m_layoutReplica.paintMask(paintInfo, adjustedPaintOffset);
     }
 }
 
 } // namespace blink