Introduce PaintPropertyTreeBuilderFragmentContext and use it throughout.

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 4f668ba96563fcf89dc87343aff4f11df29817e5..871cb8e15c1ae5c92c50d1584a02cf1d6cb8fcf7 100644
--- a/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
+++ b/third_party/WebKit/Source/core/paint/PaintPropertyTreeBuilder.h
@@ -21,12 +21,12 @@ class LayoutObject;
 // 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);
+struct PaintPropertyTreeBuilderFragmentContext {
+  USING_FAST_MALLOC(PaintPropertyTreeBuilderFragmentContext);
 
  public:
   // Initializes all property tree nodes to the roots.
-  PaintPropertyTreeBuilderContext();
+  PaintPropertyTreeBuilderFragmentContext();
 
   // State that propagates on the containing block chain (and so is adjusted
   // when an absolute or fixed position object is encountered).
@@ -68,7 +68,6 @@ struct PaintPropertyTreeBuilderContext {
   // are also inherited by containing block tree instead of DOM tree, thus they
   // are included in the additional context too.
   ContainingBlockContext absolute_position;
-  const LayoutObject* container_for_absolute_position;
 
   ContainingBlockContext fixed_position;
 
@@ -87,6 +86,24 @@ struct PaintPropertyTreeBuilderContext {
   // This variable represents the input cull of current effect, also serves as
   // output clip of child effects that don't have a hard clip.
   const ClipPaintPropertyNode* input_clip_of_current_effect;
+};
+
+struct PaintPropertyTreeBuilderContext {
+  USING_FAST_MALLOC(PaintPropertyTreeBuilderContext);
+
+ public:
+  PaintPropertyTreeBuilderContext()
+      : container_for_absolute_position(nullptr),
+        force_subtree_update(false)
+#if DCHECK_IS_ON()
+        ,
+        is_actually_needed(true)
+#endif
+  {
+  }
+
+  Vector<PaintPropertyTreeBuilderFragmentContext> fragments;
+  const LayoutObject* container_for_absolute_position;
 
   // True if a change has forced all properties in a subtree to be updated. This
   // can be set due to paint offset changes or when the structure of the
@@ -96,7 +113,7 @@ struct PaintPropertyTreeBuilderContext {
 #if DCHECK_IS_ON()
   // When DCHECK_IS_ON() we create PaintPropertyTreeBuilderContext even if not
   // needed. See FindPaintOffsetAndVisualRectNeedingUpdate.h.
-  bool is_actually_needed = true;
+  bool is_actually_needed;
 #endif
 };
 
@@ -122,45 +139,68 @@ class PaintPropertyTreeBuilder {
                                    PaintPropertyTreeBuilderContext&);
 
  private:
-  ALWAYS_INLINE static void UpdatePaintOffset(const LayoutBoxModelObject&,
-                                              PaintPropertyTreeBuilderContext&);
+  ALWAYS_INLINE static void UpdatePaintOffset(
+      const LayoutBoxModelObject&,
+      PaintPropertyTreeBuilderFragmentContext&,
+      const LayoutObject* container_for_absolute_position);
   ALWAYS_INLINE static void UpdatePaintOffsetTranslation(
       const LayoutBoxModelObject&,
-      PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateForObjectLocationAndSize(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
-  ALWAYS_INLINE static void UpdateTransform(const LayoutObject&,
-                                            PaintPropertyTreeBuilderContext&);
+      const LayoutObject* container_for_absolute_position,
+      bool& is_actually_needed,
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
+  ALWAYS_INLINE static void UpdateTransform(
+      const LayoutObject&,
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateTransformForNonRootSVG(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
-  ALWAYS_INLINE static void UpdateEffect(const LayoutObject&,
-                                         PaintPropertyTreeBuilderContext&);
-  ALWAYS_INLINE static void UpdateFilter(const LayoutObject&,
-                                         PaintPropertyTreeBuilderContext&);
-  ALWAYS_INLINE static void UpdateCssClip(const LayoutObject&,
-                                          PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
+  ALWAYS_INLINE static void UpdateEffect(
+      const LayoutObject&,
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
+  ALWAYS_INLINE static void UpdateFilter(
+      const LayoutObject&,
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
+  ALWAYS_INLINE static void UpdateCssClip(
+      const LayoutObject&,
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateLocalBorderBoxContext(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateScrollbarPaintOffset(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateOverflowClip(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
-  ALWAYS_INLINE static void UpdatePerspective(const LayoutObject&,
-                                              PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
+  ALWAYS_INLINE static void UpdatePerspective(
+      const LayoutObject&,
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateSvgLocalToBorderBoxTransform(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateScrollAndScrollTranslation(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
   ALWAYS_INLINE static void UpdateOutOfFlowContext(
       const LayoutObject&,
-      PaintPropertyTreeBuilderContext&);
+      PaintPropertyTreeBuilderFragmentContext&,
+      bool& force_subtree_update);
 
   // Ensure the ObjectPaintProperties object is created if it will be needed, or
   // cleared otherwise.