I'd like to add HeapSnapshot::GetMaxSnapshotJSObjectId function.

include/v8-profiler.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * 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
@@ skipping 329 matching lines @@
 
   /** Returns a node by its id. */
   const HeapGraphNode* GetNodeById(SnapshotObjectId id) const;
 
   /** Returns total nodes count in the snapshot. */
   int GetNodesCount() const;
 
   /** Returns a node by index. */
   const HeapGraphNode* GetNode(int index) const;
 
+  /** Returns a max seen JS object Id. */
+  SnapshotObjectId GetMaxSnapshotJSObjectId() const;
+
   /**
    * Deletes the snapshot and removes it from HeapProfiler's list.
    * All pointers to nodes, edges and paths previously returned become
    * invalid.
    */
   void Delete();
 
   /**
    * Prepare a serialized representation of the snapshot. The result
    * is written into the stream provided in chunks of specified size.
@@ skipping 151 matching lines @@
 };
 
 
 }  // namespace v8
 
 
 #undef V8EXPORT
 
 
 #endif  // V8_V8_PROFILER_H_