Merge up to 8597 to experimental/gc from the bleeding edge.

include/v8-profiler.h

Index: include/v8-profiler.h
===================================================================
--- include/v8-profiler.h	(revision 8618)
+++ include/v8-profiler.h	(working copy)
@@ -269,17 +269,10 @@
 
   /**
    * Returns node id. For the same heap object, the id remains the same
-   * across all snapshots. Not applicable to aggregated heap snapshots
-   * as they only contain aggregated instances.
+   * across all snapshots.
    */
   uint64_t GetId() const;
 
-  /**
-   * Returns the number of instances. Only applicable to aggregated
-   * heap snapshots.
-   */
-  int GetInstancesCount() const;
-
   /** Returns node's own size, in bytes. */
   int GetSelfSize() const;
 
@@ -323,9 +316,7 @@
 class V8EXPORT HeapSnapshot {
  public:
   enum Type {
-    kFull = 0,       // Heap snapshot with all instances and references.
-    kAggregated = 1  // Snapshot doesn't contain individual heap entries,
-                     // instead they are grouped by constructor name.
+    kFull = 0  // Heap snapshot with all instances and references.
   };
   enum SerializationFormat {
     kJSON = 0  // See format description near 'Serialize' method.
@@ -346,6 +337,12 @@
   /** Returns a node by its id. */
   const HeapGraphNode* GetNodeById(uint64_t id) const;
 
+  /** Returns total nodes count in the snapshot. */
+  int GetNodesCount() const;
+
+  /** Returns a node by index. */
+  const HeapGraphNode* GetNode(int index) const;
+
   /**
    * Deletes the snapshot and removes it from HeapProfiler's list.
    * All pointers to nodes, edges and paths previously returned become