Implement the framework for the paint property hierarchy

third_party/WebKit/Source/platform/graphics/paint/DisplayItemTransformTree.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 DisplayItemTransformTree_h
 #define DisplayItemTransformTree_h
 
 #include "platform/PlatformExport.h"
 #include "platform/geometry/FloatPoint3D.h"
 #include "platform/transforms/TransformationMatrix.h"
 #include "public/platform/WebDisplayItemTransformTree.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 // Represents the hierarchy of transforms which apply to ranges of a display
 // item list and may be of interest to the compositor.
 //
 // This class is also the private implementation of WebDisplayItemTransformTree.
 // For more detail, see WebDisplayItemTransformTree.h.
+// TODO(pdr): Refactor this into TransformPaintProperty.

[jbroman, 2015/10/07 15:22:22]

Yeah, we'll have to see how this evolves.

 class PLATFORM_EXPORT DisplayItemTransformTree {
 public:
     using TransformNode = WebDisplayItemTransformTree::TransformNode;
     enum : size_t { kInvalidIndex = WebDisplayItemTransformTree::kInvalidIndex };
 
     DisplayItemTransformTree();
     ~DisplayItemTransformTree();
 
     size_t nodeCount() const { return m_nodes.size(); }
     TransformNode& nodeAt(size_t index) { return m_nodes[index]; }
@@ skipping 10 matching lines @@
         return m_nodes.size() - 1;
     }
 
 private:
     Vector<TransformNode> m_nodes;
 };
 
 } // namespace blink
 
 #endif // DisplayItemTransformTree_h