Move GraphicsLayerUpdater::rebuildTree into its own file

Source/core/rendering/compositing/GraphicsLayerTreeBuilder.h

 /*
+ * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2014 Google 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#ifndef WebCompositeAndReadbackAsyncCallback_h
-#define WebCompositeAndReadbackAsyncCallback_h
+#ifndef GraphicsLayerTreeBuilder_h
+#define GraphicsLayerTreeBuilder_h
 
-class SkBitmap;
+#include "platform/graphics/GraphicsLayer.h"
+#include "wtf/Vector.h"
 
-namespace blink {
+namespace WebCore {
 
-class WebCompositeAndReadbackAsyncCallback {
+class RenderLayer;
+
+class GraphicsLayerTreeBuilder {
 public:
-    virtual void didCompositeAndReadback(const SkBitmap&) = 0;
+    GraphicsLayerTreeBuilder();
+    ~GraphicsLayerTreeBuilder();
+
+    void rebuild(RenderLayer&, GraphicsLayerVector& childLayersOfEnclosingLayer);
 };
 
-} // namespace blink
+} // namespace WebCore
 
-#endif // WebCompositeAndReadbackAsyncCallback_h
+#endif // GraphicsLayerTreeBuilder_h