Added JSON reporting to reload.

runtime/vm/object_reload.cc

Index: runtime/vm/object_reload.cc
diff --git a/runtime/vm/object_reload.cc b/runtime/vm/object_reload.cc
index 577cb910266eaaf5ed0281fe807eaa24b580ce22..c646dd63bb50452d30ebcb1d3aba7b76fcf57627 100644
--- a/runtime/vm/object_reload.cc
+++ b/runtime/vm/object_reload.cc
@@ -412,6 +412,16 @@ class TypeParametersChanged : public ClassReasonForCancelling {
     return String::NewFormatted(
         "Limitation: type parameters have changed for %s", from_.ToCString());
   }
+
+  void AppendTo(JSONArray* array) {
+    JSONObject jsobj(array);
+    jsobj.AddProperty("type", "ReasonForCancellingReload");
+    jsobj.AddProperty("kind", "TypeParametersChanged");
+    jsobj.AddProperty("class", to_);
+    jsobj.AddProperty("message",
+                      "Limitation: changing type parameters "
+                      "does not work with hot reload.");
+  }
 };