Revert of Reduce copying of local data structures in GeometryMapper and 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 1ab53d95b8ebf5c2ffe54fdb50e2e6c5f4de2839..439470c7a46c1a0ee9db1e1293e848e7ba853368 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -1646,10 +1646,9 @@
                                       overlayScrollbarClipBehavior);
     if (respectOverflowClip == IgnoreOverflowClip)
       clipRectsContext.setIgnoreOverflowClip();
-
-    enclosingPaginationLayer()
-        ->clipper(geometryMapperOption)
-        .calculateBackgroundClipRect(clipRectsContext, ancestorClipRect);
+    ancestorClipRect = enclosingPaginationLayer()
+                           ->clipper(geometryMapperOption)
+                           .backgroundClipRect(clipRectsContext);
     if (rootLayerIsInsidePaginationLayer)
       ancestorClipRect.moveBy(
           -rootLayer->visualOffsetFromAncestor(ancestorLayer));
@@ -1900,12 +1899,10 @@
 
     // Make sure the parent's clip rects have been calculated.
     if (parent()) {
-      ClipRect clipRect;
-      clipper(PaintLayer::DoNotUseGeometryMapper)
-          .calculateBackgroundClipRect(
-              ClipRectsContext(rootLayer, clipRectsCacheSlot,
-                               ExcludeOverlayScrollbarSizeForHitTesting),
-              clipRect);
+      ClipRect clipRect = clipper(PaintLayer::DoNotUseGeometryMapper)
+                              .backgroundClipRect(ClipRectsContext(
+                                  rootLayer, clipRectsCacheSlot,
+                                  ExcludeOverlayScrollbarSizeForHitTesting));
       // Go ahead and test the enclosing clip now.
       if (!clipRect.intersects(hitTestLocation))
         return nullptr;
@@ -2144,17 +2141,15 @@
     if (parent() != enclosingPaginationLayer()) {
       enclosingPaginationLayer()->convertToLayerCoords(
           rootLayer, offsetOfPaginationLayerFromRoot);
-
-      ClipRect parentClipRect;
-      clipper(PaintLayer::DoNotUseGeometryMapper)
-          .calculateBackgroundClipRect(
-              ClipRectsContext(enclosingPaginationLayer(), clipRectsCacheSlot,
-                               ExcludeOverlayScrollbarSizeForHitTesting),
-              parentClipRect);
-
+      LayoutRect parentClipRect =
+          clipper(PaintLayer::DoNotUseGeometryMapper)
+              .backgroundClipRect(ClipRectsContext(
+                  enclosingPaginationLayer(), clipRectsCacheSlot,
+                  ExcludeOverlayScrollbarSizeForHitTesting))
+              .rect();
       parentClipRect.moveBy(fragment.paginationOffset +
                             offsetOfPaginationLayerFromRoot);
-      clipRect.intersect(parentClipRect.rect());
+      clipRect.intersect(parentClipRect);
     }
 
     if (!hitTestLocation.intersects(clipRect))