New Heap profiler: fix JSON serialization of aggregated profiles.

test/cctest/test-heap-profiler.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 //
 // Tests for heap profiler
 
 #ifdef ENABLE_LOGGING_AND_PROFILING
 
 #include "v8.h"
 #include "heap-profiler.h"
 #include "snapshot.h"
 #include "string-stream.h"
@@ skipping 1160 matching lines @@
   v8::HandleScope scope;
   LocalContext env;
   const v8::HeapSnapshot* snapshot =
       v8::HeapProfiler::TakeSnapshot(v8::String::New("abort"));
   TestJSONStream stream(5);
   snapshot->Serialize(&stream, v8::HeapSnapshot::kJSON);
   CHECK_GT(stream.size(), 0);
   CHECK_EQ(0, stream.eos_signaled());
 }
 
+
+// Must not crash in debug mode.
+TEST(AggregatedHeapSnapshotJSONSerialization) {
+  v8::HandleScope scope;
+  LocalContext env;
+
+  const v8::HeapSnapshot* snapshot =
+      v8::HeapProfiler::TakeSnapshot(
+          v8::String::New("agg"), v8::HeapSnapshot::kAggregated);
+  TestJSONStream stream;
+  snapshot->Serialize(&stream, v8::HeapSnapshot::kJSON);
+  CHECK_GT(stream.size(), 0);
+  CHECK_EQ(1, stream.eos_signaled());
+}
+
 #endif  // ENABLE_LOGGING_AND_PROFILING