Build fix for Mac.

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 cb9898fc1699ae0bcf2ba402cd5e8e5b1ee8fd43..7e48a87a7ee10e7d015543da3a6a4e80cdc1f69d 100644
--- a/test/cctest/test-heap-profiler.cc
+++ b/test/cctest/test-heap-profiler.cc
@@ -707,7 +707,8 @@ class TestStatsStream : public v8::OutputStream {
       intervals_count_(0),
       first_interval_index_(-1) { }
   TestStatsStream(const TestStatsStream& stream)
-    : eos_signaled_(stream.eos_signaled_),
+    : v8::OutputStream(stream),
+      eos_signaled_(stream.eos_signaled_),
       numbers_written_(stream.numbers_written_),
       entries_count_(stream.entries_count_),
       intervals_count_(stream.intervals_count_),