Mark layer needsPaintPhaseFloat if a LayoutBlockFlow contains float

third_party/WebKit/Source/core/paint/PaintLayerPainter.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 "core/paint/PaintLayerPainter.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/layout/ClipPathOperation.h"
 #include "core/layout/LayoutBlock.h"
@@ skipping 709 matching lines @@
         clipState = HasClipped;
     }
 
     // We have to loop through every fragment multiple times, since we have to issue paint invalidations in each specific phase in order for
     // interleaving of the fragments to work properly.
     if (selectionOnly) {
         paintForegroundForFragmentsWithPhase(PaintPhaseSelection, layerFragments, context, localPaintingInfo, paintFlags, clipState);
     } else {
         if (m_paintLayer.needsPaintPhaseDescendantBlockBackgrounds())
             paintForegroundForFragmentsWithPhase(PaintPhaseDescendantBlockBackgroundsOnly, layerFragments, context, localPaintingInfo, paintFlags, clipState);
-        // TODO(wangxianzhu): Enable float empty-phase optimization after fixing crbug.com/603910.
-        // if (m_paintLayer.needsPaintPhaseFloat())
-        paintForegroundForFragmentsWithPhase(PaintPhaseFloat, layerFragments, context, localPaintingInfo, paintFlags, clipState);
+        if (m_paintLayer.needsPaintPhaseFloat())
+            paintForegroundForFragmentsWithPhase(PaintPhaseFloat, layerFragments, context, localPaintingInfo, paintFlags, clipState);
         paintForegroundForFragmentsWithPhase(PaintPhaseForeground, layerFragments, context, localPaintingInfo, paintFlags, clipState);
         if (m_paintLayer.needsPaintPhaseDescendantOutlines())
             paintForegroundForFragmentsWithPhase(PaintPhaseDescendantOutlinesOnly, layerFragments, context, localPaintingInfo, paintFlags, clipState);
     }
 }
 
 void PaintLayerPainter::paintForegroundForFragmentsWithPhase(PaintPhase phase,
     const PaintLayerFragments& layerFragments, GraphicsContext& context,
     const PaintLayerPaintingInfo& localPaintingInfo, PaintLayerFlags paintFlags, ClipState clipState)
 {
@@ skipping 51 matching lines @@
     if (!m_paintLayer.containsDirtyOverlayScrollbars())
         return;
 
     PaintLayerPaintingInfo paintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(damageRect)), paintFlags, LayoutSize());
     paintLayer(context, paintingInfo, PaintLayerPaintingOverlayScrollbars);
 
     m_paintLayer.setContainsDirtyOverlayScrollbars(false);
 }
 
 } // namespace blink