[mojo] Add pickling support for native-only structs

mojo/public/cpp/bindings/tests/pickled_struct_chromium.cc

+// Copyright 2015 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/cpp/bindings/tests/pickled_struct_chromium.h"
+
+#include "base/pickle.h"
+
+namespace mojo {
+namespace test {
+
+PickledStructChromium::PickledStructChromium() {}
+
+PickledStructChromium::PickledStructChromium(int foo, int bar)
+    : foo_(foo), bar_(bar) {
+}
+
+PickledStructChromium::~PickledStructChromium() {}
+
+}  // namespace test
+}  // namespace mojo
+
+namespace IPC {
+
+void ParamTraits<mojo::test::PickledStructChromium>::Write(
+    base::Pickle* m,
+    const param_type& p) {
+  m->WriteInt(p.foo());
+  m->WriteInt(p.bar());
+}
+
+bool ParamTraits<mojo::test::PickledStructChromium>::Read(
+    const base::Pickle* m,
+    base::PickleIterator* iter,
+    param_type* p) {
+  int foo, bar;
+  if (!iter->ReadInt(&foo) || !iter->ReadInt(&bar))
+    return false;
+
+  p->set_foo(foo);
+  p->set_bar(bar);
+  return true;
+}
+
+}  // namespace IPC