1 files changed, 39 insertions, 1 deletions
diff --git a/cc/tree_synchronizer.h b/cc/tree_synchronizer.h
index 638cbb2..2609841 100644
--- a/cc/tree_synchronizer.h
+++ b/cc/tree_synchronizer.h
@@ -1,3 +1,41 @@
-// Copyright 2012 The Chromium Authors. All rights reserved.
+// Copyright 2011 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 TreeSynchronizer_h
+#define TreeSynchronizer_h
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "cc/scoped_ptr_hash_map.h"
+
+namespace cc {
+
+class CCLayerImpl;
+class CCLayerTreeHostImpl;
+class LayerChromium;
+
+class TreeSynchronizer {
+public:
+    // Accepts a LayerChromium tree and returns a reference to a CCLayerImpl tree that duplicates the structure
+    // of the LayerChromium tree, reusing the CCLayerImpls in the tree provided by oldCCLayerImplRoot if possible.
+    static scoped_ptr<CCLayerImpl> synchronizeTrees(LayerChromium* layerRoot, scoped_ptr<CCLayerImpl> oldCCLayerImplRoot, CCLayerTreeHostImpl*);
+
+private:
+    TreeSynchronizer(); // Not instantiable.
+
+    typedef ScopedPtrHashMap<int, CCLayerImpl> ScopedPtrCCLayerImplMap;
+    typedef base::hash_map<int, CCLayerImpl*> RawPtrCCLayerImplMap;
+
+    // Declared as static member functions so they can access functions on LayerChromium as a friend class.
+    static scoped_ptr<CCLayerImpl> reuseOrCreateCCLayerImpl(RawPtrCCLayerImplMap& newLayers, ScopedPtrCCLayerImplMap& oldLayers, LayerChromium*);
+    static void collectExistingCCLayerImplRecursive(ScopedPtrCCLayerImplMap& oldLayers, scoped_ptr<CCLayerImpl>);
+    static scoped_ptr<CCLayerImpl> synchronizeTreeRecursive(RawPtrCCLayerImplMap& newLayers, ScopedPtrCCLayerImplMap& oldLayers, LayerChromium*, CCLayerTreeHostImpl*);
+    static void updateScrollbarLayerPointersRecursive(const RawPtrCCLayerImplMap& newLayers, LayerChromium*);
+
+    DISALLOW_COPY_AND_ASSIGN(TreeSynchronizer);
+};
+
+} // namespace cc
+
+#endif // TreeSynchronizer_h