Skip paint chunks with effectively invisible opacity.

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

Index: third_party/WebKit/Source/core/paint/PaintLayerPainter.h
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerPainter.h b/third_party/WebKit/Source/core/paint/PaintLayerPainter.h
index fd3922cb2ba8402dbc49d815abbfdea1e306f6e7..a901a14535c98f866e10cca200a0dc0bb353dae4 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerPainter.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayerPainter.h
@@ -54,8 +54,6 @@ class CORE_EXPORT PaintLayerPainter {
                               const GlobalPaintFlags);
 
  private:
-  friend class PaintLayerPainterTest;
-
   enum ClipState { kHasNotClipped, kHasClipped };
 
   inline bool IsFixedPositionObjectInPagedMedia();
@@ -146,10 +144,6 @@ class CORE_EXPORT PaintLayerPainter {
   bool ShouldPaintLayerInSoftwareMode(const GlobalPaintFlags,
                                       PaintLayerFlags paint_flags);
 
-  // Returns true if the painted output of this PaintLayer and its children is
-  // invisible and therefore can't impact painted output.
-  bool PaintedOutputInvisible(const PaintLayerPaintingInfo&);
-
   PaintLayer& paint_layer_;
 };