Detailed heap snapshot usability improvement.

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index 27b3c6def3f5431d95e524f8a6cfbccc91f4524b..bcca65edbcab607196694d06e15b2464828f5253 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -476,12 +476,23 @@ class V8EXPORT RetainedObjectInfo {  // NOLINT
   virtual intptr_t GetHash() = 0;
 
   /**
-   * Returns human-readable label. It must be a NUL-terminated UTF-8
+   * Returns human-readable label. It must be a null-terminated UTF-8
    * encoded string. V8 copies its contents during a call to GetLabel.
    */
   virtual const char* GetLabel() = 0;
 
   /**
+   * Returns human-readable group label. It must be a null-terminated UTF-8
+   * encoded string. V8 copies its contents during a call to GetGroupLabel.
+   * Heap snapshot generator will collect all the group names, create
+   * top level entries with these names and attach the objects to the
+   * corresponding top level group objects. There is a default
+   * implementation which is required because embedders don't have their
+   * own implementation yet.
+   */
+  virtual const char* GetGroupLabel() { return GetLabel(); }
+
+  /**
    * Returns element count in case if a global handle retains
    * a subgraph by holding one of its nodes.
    */