[mojo] Add pickling support for native-only structs

mojo/public/cpp/bindings/tests/pickled_struct_blink.h

+// 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.
+
+#ifndef MOJO_PUBLIC_CPP_BINDINGS_TESTS_PICKLED_STRUCT_BLINK_H_
+#define MOJO_PUBLIC_CPP_BINDINGS_TESTS_PICKLED_STRUCT_BLINK_H_
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/macros.h"
+#include "ipc/ipc_param_traits.h"
+
+namespace base {
+class Pickle;
+class PickleIterator;
+}
+
+namespace mojo {
+namespace test {
+
+// An implementation of a hypothetical PickledStruct type specifically for
+// consumers in Blink.
+//
+// To make things slightly more interesting, this variation of the type doesn't
+// support negative values. It'll DCHECK if you try to construct it with any,
+// and it will fail deserialization if negative values are decoded.
+class PickledStructBlink {
+ public:
+  PickledStructBlink();
+  PickledStructBlink(int foo, int bar);
+  ~PickledStructBlink();
+
+  int foo() const { return foo_; }
+  void set_foo(int foo) { DCHECK_GE(foo, 0); foo_ = foo; }

[yzshen1, 2015/12/15 21:20:27]

Style! :) Please put each statement on a separate line.

[Ken Rockot(use gerrit already), 2015/12/15 23:31:08]

OK - I took some liberties because it's test-only code, but I think you're
right:)

+
+  int bar() const { return bar_; }
+  void set_bar(int bar) { DCHECK_GE(bar, 0); bar_ = bar; }

[yzshen1, 2015/12/15 21:20:27]

ditto.

[Ken Rockot(use gerrit already), 2015/12/15 23:31:08]

done

+
+ private:
+  int foo_ = 0, bar_ = 0;

[yzshen1, 2015/12/15 21:20:27]

I believe they should be on separate lines, too.

[Ken Rockot(use gerrit already), 2015/12/15 23:31:08]

done

+
+  DISALLOW_COPY_AND_ASSIGN(PickledStructBlink);
+};
+
+}  // namespace test
+}  // namespace mojo
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mojo::test::PickledStructBlink> {
+  using param_type = mojo::test::PickledStructBlink;
+
+  static size_t GetSize(const param_type& p) { return 8; }
+  static void Write(base::Pickle* m, const param_type& p);
+  static bool Read(const base::Pickle* m,
+                   base::PickleIterator* iter,
+                   param_type* r);
+  static void Log(const param_type& p, std::string* l) {}
+};
+
+}  // namespace IPC
+
+#endif  // MOJO_PUBLIC_CPP_BINDINGS_TESTS_PICKLED_STRUCT_BLINK_H_