Allow arbitrary names for weak references in heap snapshots.

test/cctest/test-heap-profiler.cc

Index: test/cctest/test-heap-profiler.cc
diff --git a/test/cctest/test-heap-profiler.cc b/test/cctest/test-heap-profiler.cc
index 39b12c9e87414c4595c12e074f57b02d17eeed44..fdaf9fa6c9a7fa111848b0b20bc57f39aa087fe4 100644
--- a/test/cctest/test-heap-profiler.cc
+++ b/test/cctest/test-heap-profiler.cc
@@ -2337,6 +2337,6 @@ TEST(ArrayBufferAndArrayBufferView) {
       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);
 }