[profiler] Add missing node type name.

Bug: v8:6968
Change-Id: Ibb19e96b6ce8ad56356ab6c4fb6bbc588bbb7420
Reviewed-on: https://chromium-review.googlesource.com/729248
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48799}

AUTHORS

-# Below is a list of people and organizations that have contributed
+# Below is a list of people and organizations that have contributed
 # to the V8 project.  Names should be added to the list like so:
 #
 #   Name/Organization <email address>
@@ -86,6 +86,7 @@ JunHo Seo <sejunho@gmail.com>
 Kang-Hao (Kenny) Lu <kennyluck@csail.mit.edu>
 Karl Skomski <karl@skomski.com>
 Kevin Gibbons <bakkot@gmail.com>
+Kris Selden <kris.selden@gmail.com>
 Loo Rong Jie <loorongjie@gmail.com>
 Luis Reis <luis.m.reis@gmail.com>
 Luke Zarko <lukezarko@gmail.com>
@@ -138,3 +139,4 @@ Yu Yin <xwafish@gmail.com>
 Zac Hansen <xaxxon@gmail.com>
 Zhongping Wang <kewpie.w.zp@gmail.com>
 柳荣一 <admin@web-tinker.com>
+

src/profiler/heap-snapshot-generator.cc

@@ -2669,7 +2669,8 @@ void HeapSnapshotJSONSerializer::SerializeSnapshot() {
             JSON_S("native") ","
             JSON_S("synthetic") ","
             JSON_S("concatenated string") ","
-            JSON_S("sliced string")) ","
+            JSON_S("sliced string") ","
+            JSON_S("symbol")) ","
         JSON_S("string") ","
         JSON_S("number") ","
         JSON_S("number") ","