Add missing <stdlib.h> to validation_parser.cc.

mojo/public/interfaces/bindings/tests/validation_parser/validation_parser.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mojo/public/interfaces/bindings/tests/validation_parser/validation_parser.h"
 
+#include <stdlib.h>
+
 #include "mojo/public/cpp/bindings/tests/validation_test_input_parser.h"
 
 // C interface for the validation test parser.
 //
 // This routine malloc()s return error and space for data which
 // must be freed by the caller. Returns a null pointer in *data
 // and a message in *(return value) on failure. Returns a valid
 // pointer and size in *data and *data_len on success, and a
 // null pointer in *(return value).
 extern "C" char* ParseValidationTest(const char* input,    // Input
@@ skipping 25 matching lines @@
     *data_len = cpp_data_size;
     // Copy the parsed output into the buffer.
     memcpy(*data, cpp_data.data(), cpp_data_size);
   } else {
     // If we have no data, set the pointer to null and size to 0.
     *data = nullptr;
     *data_len = 0;
   }
   return nullptr;
 }