[SPv2] Introduce an option to output the GraphicsLayer tree as a flat layer list.

third_party/WebKit/Source/core/testing/Internals.idl

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 169 matching lines @@
     readonly attribute unsigned long workerThreadCount;
 
     // Flags for layerTreeAsText.
     // The values of these constants must be kept in sync with the values of LayerTreeFlags in GraphicsLayerClient.h.
     const unsigned short LAYER_TREE_INCLUDES_DEBUG_INFO = 1;
     const unsigned short LAYER_TREE_INCLUDES_PAINT_INVALIDATIONS = 2;
     const unsigned short LAYER_TREE_INCLUDES_PAINTING_PHASES = 4;
     const unsigned short LAYER_TREE_INCLUDES_ROOT_LAYER = 8;
     const unsigned short LAYER_TREE_INCLUDES_CLIP_AND_SCROLL_PARENTS = 16;
     const unsigned short LAYER_TREE_INCLUDES_COMPOSITING_REASONS = 32;
+    const unsigned short OUTPUT_CHILDREN_AS_LAYER_LIST = 64;

[Xianzhu, 2016/09/30 23:19:38]

Nit: Should we use the same prefix as the existing flags?

[chrishtr, 2016/09/30 23:20:53]

The other ones all say LAYER_TREE, which seemed confusing to combine with
LAYER_LIST in the same breath.

[Xianzhu, 2016/10/01 00:14:03]

Acknowledged.

+
     [RaisesException] DOMString layerTreeAsText(Document document, optional unsigned short flags);
     [RaisesException] DOMString elementLayerTreeAsText(Element element, optional unsigned short flags);
 
     [RaisesException] boolean scrollsWithRespectTo(Element element1, Element element2);
 
     DOMString scrollingStateTreeAsText(Document document);
     [RaisesException] DOMString mainThreadScrollingReasons(Document document);
     [RaisesException] ClientRectList nonFastScrollableRects(Document document);
 
     void evictAllResources();
@@ skipping 154 matching lines @@
     DOMString getScrollAnimationState(Node node);
 
     DOMString getProgrammaticScrollAnimationState(Node node);
 
     ClientRect visualRect(Node node);
 
     OriginTrialsTest originTrialsTest();
 
     void crash();
 };