Allow arbitrary names for weak references in heap snapshots.

test/cctest/test-heap-profiler.cc

 // Copyright 2011 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 2319 matching lines @@
       heap_profiler->TakeHeapSnapshot(v8_str("snapshot"));
   CHECK(ValidateSnapshot(snapshot));
   const v8::HeapGraphNode* global = GetGlobalObject(snapshot);
   const v8::HeapGraphNode* arr1_obj =
       GetProperty(global, v8::HeapGraphEdge::kProperty, "arr1");
   CHECK_NE(NULL, arr1_obj);
   const v8::HeapGraphNode* arr1_buffer =
       GetProperty(arr1_obj, v8::HeapGraphEdge::kInternal, "buffer");
   CHECK_NE(NULL, arr1_buffer);
   const v8::HeapGraphNode* first_view =
-      GetProperty(arr1_buffer, v8::HeapGraphEdge::kWeak, "2");
+      GetProperty(arr1_buffer, v8::HeapGraphEdge::kWeak, "weak_first_view");
   CHECK_NE(NULL, first_view);
 }