Collect edge count profiling data and reorder basic blocks.

runtime/vm/block_scheduler.h

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_BLOCK_SCHEDULER_H_
+#define VM_BLOCK_SCHEDULER_H_
+
+#include "vm/allocation.h"
+
+namespace dart {
+
+class FlowGraph;
+
+class BlockScheduler : public ValueObject {
+ public:
+  explicit BlockScheduler(FlowGraph* flow_graph) : flow_graph_(flow_graph) { }
+
+  FlowGraph* flow_graph() const { return flow_graph_; }
+
+  void AssignEdgeWeights() const;
+
+  void ReorderBlocks() const;
+
+ private:
+  FlowGraph* const flow_graph_;
+};
+
+}  // namespace dart
+
+#endif  // VM_BLOCK_SCHEDULER_H_