Add ArrayTraits<CArray<T>> utility template

gpu/ipc/common/mailbox_struct_traits.h

 // 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.
 
 #ifndef GPU_IPC_COMMON_MAILBOX_STRUCT_TRAITS_H_
 #define GPU_IPC_COMMON_MAILBOX_STRUCT_TRAITS_H_
 
 #include "gpu/command_buffer/common/mailbox.h"
 #include "gpu/ipc/common/mailbox.mojom.h"
 #include "mojo/public/cpp/bindings/array_traits.h"
 
 namespace mojo {
 
 // A buffer used to read bytes directly from MailboxDataView to gpu::Mailbox
 // name.
-struct MailboxName {
-  int8_t* data;
-};
-
-// ArrayTraits needed for ReadName use with MailboxName.
-template <>
-struct ArrayTraits<MailboxName> {
-  using Element = int8_t;
-  static size_t GetSize(const MailboxName& b);
-  static int8_t* GetData(MailboxName& b);
-  static const int8_t* GetData(const MailboxName& b);
-  static int8_t& GetAt(MailboxName& b, size_t i);
-  static const int8_t& GetAt(const MailboxName& b, size_t i);
-  static bool Resize(MailboxName& b, size_t size);
-};
+using MailboxName = CArray<int8_t>;
 
 template <>
 struct StructTraits<gpu::mojom::Mailbox, gpu::Mailbox> {
   static MailboxName name(const gpu::Mailbox& mailbox);
   static bool Read(gpu::mojom::MailboxDataView data, gpu::Mailbox* out);
 };
 
 }  // namespace mojo
 
 #endif  // GPU_IPC_COMMON_MAILBOX_STRUCT_TRAITS_H_