[SPInvalidation, SPv2] Compute paint offset for paginated content

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

Index: third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
diff --git a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
index b86ac35b42a4954b3cf3c7ad1a5bc522444aaea4..7177cfe71e8692d1a349eee3df9d15a7d5384e13 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
@@ -17,6 +17,7 @@ namespace blink {
 class FrameView;
 class LayoutBoxModelObject;
 class LayoutObject;
+class PaintLayer;
 
 // The context for PaintPropertyTreeBuilder.
 // It's responsible for bookkeeping tree state in other order, for example, the
@@ -36,6 +37,8 @@ struct PaintPropertyTreeBuilderContext {
     // to refer the object's border box, then the callee will derive its own
     // border box by translating the space with its own layout location.
     const TransformPaintPropertyNode* transform = nullptr;
+    // The PaintLayer that owns |transform|.
+    const PaintLayer* transform_paint_layer = nullptr;
     LayoutPoint paint_offset;
     // Whether newly created children should flatten their inherited transform
     // (equivalently, draw into the plane of their parent). Should generally