Add v8::HeapGraphNode::GetHeapValue method.

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index 4febcb95969c15ce26df218ec4b74b852def4c71..f67646f54e77d90668e50491382777a46cd10d7b 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -307,6 +307,12 @@ class V8EXPORT HeapGraphNode {
    * path from the snapshot root to the current node.
    */
   const HeapGraphNode* GetDominatorNode() const;
+
+  /**
+   * Finds and returns a value from the heap corresponding to this node,
+   * if the value is still reachable.
+   */
+  Handle<Value> GetHeapValue() const;
 };