Use intersection observer to control frame throttling

third_party/WebKit/Source/core/layout/svg/SVGLayoutSupport.cpp

 /*
  * Copyright (C) 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Google, Inc.  All rights reserved.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 142 matching lines @@
   // LayoutSVGRoot's mapLocalToAncestor method expects CSS box coordinates.
   if (parent->isSVGRoot())
     transformState.applyTransform(
         toLayoutSVGRoot(parent)->localToBorderBoxTransform());
 
   parent->mapLocalToAncestor(ancestor, transformState, flags);
 }
 
 void SVGLayoutSupport::mapAncestorToLocal(const LayoutObject& object,
                                           const LayoutBoxModelObject* ancestor,
-                                          TransformState& transformState) {
+                                          TransformState& transformState,
+                                          MapCoordinatesFlags flags) {
   // |object| is either a LayoutSVGModelObject or a LayoutSVGBlock here. In
   // the former case, |object| can never be an ancestor while in the latter
   // the caller is responsible for doing the ancestor check. Because of this,
   // computing the transform to the SVG root is always what we want to do here.
   ASSERT(ancestor != &object);
   ASSERT(object.isSVGContainer() || object.isSVGShape() ||
          object.isSVGImage() || object.isSVGText() ||
          object.isSVGForeignObject());
   AffineTransform localToSVGRoot;
   const LayoutSVGRoot& svgRoot =
       computeTransformToSVGRoot(object, localToSVGRoot);
 
-  MapCoordinatesFlags mode = UseTransforms | ApplyContainerFlip;
+  MapCoordinatesFlags mode = flags | UseTransforms | ApplyContainerFlip;
   svgRoot.mapAncestorToLocal(ancestor, transformState, mode);
 
   transformState.applyTransform(localToSVGRoot);
 }
 
 const LayoutObject* SVGLayoutSupport::pushMappingToContainer(
     const LayoutObject* object,
     const LayoutBoxModelObject* ancestorToStopAt,
     LayoutGeometryMap& geometryMap) {
   DCHECK_NE(ancestorToStopAt, object);
@@ skipping 458 matching lines @@
 }
 
 LayoutObject* SVGLayoutSupport::findClosestLayoutSVGText(
     LayoutObject* layoutObject,
     const FloatPoint& point) {
   return searchTreeForFindClosestLayoutSVGText(layoutObject, point)
       .candidateLayoutObject;
 }
 
 }  // namespace blink