[SPInvalidation, SPv2] Compute paint offset for paginated content

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PaintPropertyTreeBuilder_h
 #define PaintPropertyTreeBuilder_h
 
 #include "platform/geometry/LayoutPoint.h"
 #include "platform/graphics/paint/ClipPaintPropertyNode.h"
 #include "platform/graphics/paint/EffectPaintPropertyNode.h"
 #include "platform/graphics/paint/ScrollPaintPropertyNode.h"
 #include "platform/graphics/paint/TransformPaintPropertyNode.h"
 #include "platform/wtf/RefPtr.h"
 
 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
 // most recent position container seen.
 struct PaintPropertyTreeBuilderContext {
   USING_FAST_MALLOC(PaintPropertyTreeBuilderContext);
 
  public:
   // Initializes all property tree nodes to the roots.
   PaintPropertyTreeBuilderContext();
 
   // State that propagates on the containing block chain (and so is adjusted
   // when an absolute or fixed position object is encountered).
   struct ContainingBlockContext {
     // The combination of a transform and paint offset describes a linear space.
     // When a layout object recur to its children, the main context is expected
     // 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
     // be updated whenever |transform| is; flattening only needs to happen
     // to immediate children.
     bool should_flatten_inherited_transform = false;
     // Rendering context for 3D sorting. See
     // TransformPaintPropertyNode::renderingContextId.
     unsigned rendering_context_id = 0;
     // The clip node describes the accumulated raster clip for the current
@@ skipping 110 matching lines @@
       const LayoutObject&,
       PaintPropertyTreeBuilderContext&);
   ALWAYS_INLINE static void UpdateOutOfFlowContext(
       const LayoutObject&,
       PaintPropertyTreeBuilderContext&);
 };
 
 }  // namespace blink
 
 #endif  // PaintPropertyTreeBuilder_h