Fix a leak in TestingJsonParser.

components/safe_json/testing_json_parser.cc

Index: components/safe_json/testing_json_parser.cc
diff --git a/components/safe_json/testing_json_parser.cc b/components/safe_json/testing_json_parser.cc
index ea7e9c5469b45cc7378fa0cffe6df8ee75dce7ad..f7c81198d86971dcdfe93237a42b6ecd8d83baff 100644
--- a/components/safe_json/testing_json_parser.cc
+++ b/components/safe_json/testing_json_parser.cc
@@ -48,11 +48,12 @@ void TestingJsonParser::Start() {
   scoped_ptr<base::Value> value = base::JSONReader::ReadAndReturnError(
       unsafe_json_, base::JSON_PARSE_RFC, &error_code, &error);
 
-  // Run the callback asynchronously.
+  // Run the callback asynchronously. Post the delete task first, so that the
+  // completion callbacks may quit the run loop without leaking |this|.
+  base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);
   base::MessageLoop::current()->PostTask(
       FROM_HERE, value ? base::Bind(success_callback_, base::Passed(&value))
                        : base::Bind(error_callback_, error));
-  base::MessageLoop::current()->DeleteSoon(FROM_HERE, this);

[Bernhard Bauer, 2015/12/16 08:48:00]

Hm… in principle we could also delete this object directly here, no? No one else
has a pointer to it anyway.

[Robert Sesek, 2015/12/16 15:55:48]

Yeah, that's true, but there's no real difference from this, though.

 }
 
 }  // namespace