Remove paintOffsetTranslation for fixed-position elements.

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 2735 matching lines @@
   return m_rareData && m_rareData->compositedLayerMapping &&
          m_rareData->compositedLayerMapping->hasMaskLayer();
 }
 
 bool PaintLayer::hasCompositedClippingMask() const {
   return m_rareData && m_rareData->compositedLayerMapping &&
          m_rareData->compositedLayerMapping->hasChildClippingMaskLayer();
 }
 
 bool PaintLayer::paintsWithTransform(GlobalPaintFlags globalPaintFlags) const {
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
+    return transform();
   return (transform() ||
           layoutObject()->style()->position() == FixedPosition) &&
          ((globalPaintFlags & GlobalPaintFlattenCompositingLayers) ||
           compositingState() != PaintsIntoOwnBacking);
 }
 
 bool PaintLayer::compositesWithTransform() const {
   return transformAncestor() || transform();
 }
 
@@ skipping 522 matching lines @@
 }
 
 void showLayerTree(const blink::LayoutObject* layoutObject) {
   if (!layoutObject) {
     LOG(INFO) << "Cannot showLayerTree. Root is (nil)";
     return;
   }
   showLayerTree(layoutObject->enclosingLayer());
 }
 #endif