Store previous painting clip rects on FragmentData.

third_party/WebKit/Source/core/layout/LayoutObject.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  *               (http://www.torchmobile.com/)
@@ skipping 3564 matching lines @@
 
 LayoutRect LayoutObject::DebugRect() const {
   LayoutRect rect;
   LayoutBlock* block = ContainingBlock();
   if (block)
     block->AdjustChildDebugRect(rect);
 
   return rect;
 }
 
+FragmentData* LayoutObject::MutableForPainting::FirstFragment() {
+  if (auto* paint_data = layout_object_.GetRarePaintData())
+    return paint_data->Fragment();
+  return nullptr;
+}
+
+FragmentData& LayoutObject::MutableForPainting::EnsureFirstFragment() {
+  return layout_object_.EnsureRarePaintData().EnsureFragment();
+}
+
 void LayoutObject::InvalidatePaintForSelection() {
   // setSelectionState() propagates the state up the containing block chain to
   // tell if a block contains selected nodes or not. If this layout object is
   // not a block, we need to get the selection state from the containing block
   // to tell if we have any selected node children.
   LayoutBlock* block =
       IsLayoutBlock() ? ToLayoutBlock(this) : ContainingBlock();
   if (!block)
     return;
   if (!block->HasSelectedChildren())
@@ skipping 40 matching lines @@
     const blink::LayoutObject* root = object1;
     while (root->Parent())
       root = root->Parent();
     root->ShowLayoutTreeAndMark(object1, "*", object2, "-", 0);
   } else {
     WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
   }
 }
 
 #endif