Move scroll paint property nodes to be owned by the transform tree

third_party/WebKit/Source/platform/graphics/paint/PropertyTreeState.cpp

 // Copyright 2016 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.
 
 #include "platform/graphics/paint/PropertyTreeState.h"
 
 #include "platform/graphics/paint/GeometryMapper.h"
 
 namespace blink {
 
@@ skipping 81 matching lines @@
     case PropertyTreeState::None:
       return nullptr;
   }
   return nullptr;
 }
 
 #if DCHECK_IS_ON()
 
 String PropertyTreeState::toTreeString() const {
   return transform()->toTreeString() + "\n" + clip()->toTreeString() + "\n" +
-         effect()->toTreeString() + "\n" + scroll()->toTreeString();

[chrishtr, 2017/01/26 21:22:58]

Still useful to print the scroll independently?

[pdr., 2017/01/27 20:09:33]

The scroll tree is now printed via the transform->toTreeString. The transform
nodes are now printed with scroll info if it exists, or without scroll info
otherwise.

The output looks like:
root 0x1c3c39d9c010 parent=0x0 transform=identity ... scroll=... clip=0x0
bounds=0x0 userScrollableHorizontal=no userScrollableVertical=no ...
  PreTranslation (FrameView) 0x1c3c39d9c100 parent=0x1c3c39d9c010
transform=identity ...

(I'll see if we can make this less verbose by removing some scroll printing in
the default case)

+         effect()->toTreeString();
 }
 
 #endif
 
 }  // namespace blink