Add v8::HeapGraphNode::GetHeapValue method.

src/profile-generator.h

Index: src/profile-generator.h
diff --git a/src/profile-generator.h b/src/profile-generator.h
index 61a9463116b670889d87af1e6dbf6b6320a83081..a3b0f1a14a21b39f6af6cc9d3d112b58e9d2ca56 100644
--- a/src/profile-generator.h
+++ b/src/profile-generator.h
@@ -588,6 +588,8 @@ class HeapEntry BASE_EMBEDDED {
 
   void Print(int max_depth, int indent);
 
+  Handle<HeapObject> GetHeapObject();
+
   static int EntriesSize(int entries_count,
                          int children_count,
                          int retainers_count);
@@ -766,6 +768,7 @@ class HeapSnapshotsCollection {
   TokenEnumerator* token_enumerator() { return token_enumerator_; }
 
   uint64_t GetObjectId(Address addr) { return ids_.FindObject(addr); }
+  Handle<HeapObject> FindHeapObjectById(uint64_t id);
   void ObjectMoveEvent(Address from, Address to) { ids_.MoveObject(from, to); }
 
  private: