cc: Create a Region class that wraps SkRegion, to replace use of WebCore::Region.

cc/layer_sorter.cc

 // 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.
 
 #include "config.h"
 
 #include "cc/layer_sorter.h"
 
+#include <algorithm>
 #include <deque>
 #include <limits>
 #include <vector>
 
 #include "base/logging.h"
 #include "cc/math_util.h"
 #include "cc/render_surface_impl.h"
 #include <public/WebTransformationMatrix.h>
 
 using namespace std;
@@ skipping 388 matching lines @@
         *it = sortedList[count++]->layer;
 
     DVLOG(2) << "Sorting end ----";
 
     m_nodes.clear();
     m_edges.clear();
     m_activeEdges.clear();
 }
 
 }  // namespace cc