Use GeometryMapper in PaintLayerClipper.

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

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index 168383e4077bc5da12b3a5d8b84841d30bb4efcc..73233c4b672ff8585df3b1aaf54e73a5856f8733 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -2989,6 +2989,15 @@ void PaintLayer::styleDidChange(StyleDifference diff,
   layoutObject()->setNeedsPaintPropertyUpdate();
 }
 
+PaintLayerClipper PaintLayer::clipper() const {
+  GeometryMapper* geometryMapper = nullptr;
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled()) {
+    if (FrameView* frameView = m_layoutObject->document().view())
+      geometryMapper = frameView->geometryMapper();
+  }
+  return PaintLayerClipper(*this, geometryMapper);
+}
+
 bool PaintLayer::scrollsOverflow() const {
   if (PaintLayerScrollableArea* scrollableArea = this->getScrollableArea())
     return scrollableArea->scrollsOverflow();