Generate a templated Clone method for all mojo structs.

mojo/public/cpp/bindings/tests/struct_traits_unittest.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 "base/bind.h"
 #include "base/callback.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "mojo/public/cpp/bindings/binding_set.h"
@@ skipping 224 matching lines @@
     EXPECT_EQ(input.get_uint64(), passed.get_uint64());
     EXPECT_EQ(input.get_string(), passed.get_string());
     EXPECT_EQ(input.get_string_array(), passed.get_string_array());
     EXPECT_EQ(input.get_struct(), passed.get_struct());
     EXPECT_EQ(input.get_struct_array(), passed.get_struct_array());
     loop.Quit();
   });
   loop.Run();
 }
 
+TEST_F(StructTraitsTest, CloneStructWithTraitsContainer) {
+  StructWithTraitsContainerPtr container = StructWithTraitsContainer::New();
+  container->f_struct.set_uint32(7);
+  container->f_struct.set_uint64(42);
+  StructWithTraitsContainerPtr cloned_container = container.Clone();
+  EXPECT_EQ(7u, cloned_container->f_struct.get_uint32());
+  EXPECT_EQ(42u, cloned_container->f_struct.get_uint64());
+
+}
+
 TEST_F(StructTraitsTest, EchoPassByValueStructWithTraits) {
   MessagePipe mp;
   PassByValueStructWithTraitsImpl input;
   input.get_mutable_handle().reset(mp.handle0.release());
 
   base::RunLoop loop;
   TraitsTestServicePtr proxy = GetTraitsTestProxy();
 
   ScopedMessagePipeHandle received;
   proxy->EchoPassByValueStructWithTraits(
@@ skipping 20 matching lines @@
   uint32_t buffer_size = static_cast<uint32_t>(sizeof(buffer));
   EXPECT_EQ(MOJO_RESULT_OK,
             ReadMessageRaw(received.get(), buffer, &buffer_size, nullptr,
                            nullptr, MOJO_READ_MESSAGE_FLAG_NONE));
   EXPECT_EQ(kHelloSize, buffer_size);
   EXPECT_STREQ(kHello, buffer);
 }
 
 }  // namespace test
 }  // namespace mojo