Mojom structs for copy requests / results should map to unique_ptr

cc/ipc/copy_output_result_struct_traits.cc

 // Copyright 2017 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 "cc/ipc/copy_output_result_struct_traits.h"
 
 namespace mojo {
 
 // static
-bool StructTraits<cc::mojom::CopyOutputResultDataView, cc::CopyOutputResult>::
-    Read(cc::mojom::CopyOutputResultDataView data, cc::CopyOutputResult* out) {
+bool StructTraits<cc::mojom::CopyOutputResultDataView,
+                  std::unique_ptr<cc::CopyOutputResult>>::
+    Read(cc::mojom::CopyOutputResultDataView data,
+         std::unique_ptr<cc::CopyOutputResult>* out_p) {
+  std::unique_ptr<cc::CopyOutputResult>& out = *out_p;
+  out = cc::CopyOutputResult::CreateEmptyResult();
   out->bitmap_ = base::MakeUnique<SkBitmap>();
   return data.ReadSize(&out->size_) && data.ReadBitmap(out->bitmap_.get()) &&
          data.ReadTextureMailbox(&out->texture_mailbox_);
 }
 
 // static
-const SkBitmap&
-StructTraits<cc::mojom::CopyOutputResultDataView, cc::CopyOutputResult>::bitmap(
-    const cc::CopyOutputResult& result) {
+const SkBitmap& StructTraits<cc::mojom::CopyOutputResultDataView,
+                             std::unique_ptr<cc::CopyOutputResult>>::
+    bitmap(const std::unique_ptr<cc::CopyOutputResult>& result) {
   static SkBitmap* null_bitmap = new SkBitmap();
-  if (!result.bitmap_)
+  if (!result->bitmap_)
     return *null_bitmap;
-  return *result.bitmap_;
+  return *result->bitmap_;
 }
 
 }  // namespace mojo