Preparation for enabling slimming paint synchronized painting

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

Index: third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
index 40c3eaac3ce8f857733a781fbf3a12719f22dfff..0d4fbde5749b717b763d0a2f9b56868bc2029e8c 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
@@ -72,10 +72,8 @@ PaintLayerPainter::PaintResult PaintLayerPainter::paintLayer(GraphicsContext* co
 
     // Non self-painting layers without self-painting descendants don't need to be painted as their
     // layoutObject() should properly paint itself.
-    if (!m_paintLayer.isSelfPaintingLayer() && !m_paintLayer.hasSelfPaintingLayerDescendant()) {
-        ASSERT(!m_paintLayer.needsRepaint() || !RuntimeEnabledFeatures::slimmingPaintV2Enabled());
+    if (!m_paintLayer.isSelfPaintingLayer() && !m_paintLayer.hasSelfPaintingLayerDescendant())
         return FullyPainted;
-    }
 
     if (shouldSuppressPaintingLayer(&m_paintLayer))
         return FullyPainted;
@@ -479,9 +477,10 @@ PaintLayerPainter::PaintResult PaintLayerPainter::paintChildren(unsigned childre
 
     Optional<SubsequenceRecorder> subsequenceRecorder;
     if (!paintingInfo.disableSubsequenceCache
+        && !context->printing()
+        && m_paintLayer.isSelfPaintingLayer()

[Xianzhu, 2015/10/28 18:10:23]

This avoids unnecessary subsequence display items for non-self-painting layer
having self-painting descendants.

         && !(paintingInfo.globalPaintFlags() & GlobalPaintFlattenCompositingLayers)
-        && !(paintFlags & PaintLayerPaintingReflection)
-        && !(paintFlags & PaintLayerPaintingRootBackgroundOnly)) {
+        && !(paintFlags & (PaintLayerPaintingReflection | PaintLayerPaintingRootBackgroundOnly | PaintLayerPaintingOverlayScrollbars))) {
         if (!m_paintLayer.needsRepaint()
             && paintingInfo.scrollOffsetAccumulation == m_paintLayer.previousScrollOffsetAccumulationForPainting()
             && SubsequenceRecorder::useCachedSubsequenceIfPossible(*context, m_paintLayer, subsequenceType))