Slimming Paint phase 2 compositing algorithm plumbing

Source/core/compositing/DisplayListCompositingBuilder.h

Index: Source/core/compositing/DisplayListCompositingBuilder.h
diff --git a/Source/core/compositing/DisplayListCompositingBuilder.h b/Source/core/compositing/DisplayListCompositingBuilder.h
new file mode 100644
index 0000000000000000000000000000000000000000..aca480302efb8458053f0e807f5ba99ccd2da5a7
--- /dev/null
+++ b/Source/core/compositing/DisplayListCompositingBuilder.h
@@ -0,0 +1,35 @@
+// 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 DisplayListCompositingBuilder_h
+#define DisplayListCompositingBuilder_h
+
+#include "core/CoreExport.h"
+#include "platform/graphics/paint/DisplayItemList.h"
+#include "platform/graphics/paint/DisplayItemTransformTree.h"
+
+namespace blink {
+
+struct CompositedDisplayList {
+    // TODO(pdr): We still need to add more data here such as the simple layers
+    // and other property trees here.
+    OwnPtr<const DisplayItemTransformTree> transformTree;
+};
+
+class CORE_EXPORT DisplayListCompositingBuilder {
+public:
+    DisplayListCompositingBuilder(const DisplayItemList& displayItemList, const DisplayListDiff& displayListDiff)
+        : m_displayItemList(displayItemList)
+        , m_displayListDiff(displayListDiff) { }
+
+    CompositedDisplayList build();

[chrishtr, 2015/08/14 00:17:19]

void build(CompositedDisplayList&)

[pdr., 2015/08/14 17:28:18]

Done

I also did some minor cleanup of this file: updated the CompositedDisplayList
comment and removed the currently unused m_displayListDiff (but kept the
argument since it forms the api).

+
+private:
+    const DisplayItemList& m_displayItemList;
+    const DisplayListDiff& m_displayListDiff;
+};
+
+} // namespace blink
+
+#endif // DisplayListCompositingBuilder_h