Improve process launch handle sharing API.

content/browser/file_descriptor_info_impl.h

-// Copyright (c) 2012 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 CONTENT_BROWSER_FILE_DESCRIPTOR_INFO_IMPL_H_
-#define CONTENT_BROWSER_FILE_DESCRIPTOR_INFO_IMPL_H_
-
-#include <stddef.h>
-
-#include <map>
-#include <memory>
-#include <vector>
-
-#include "base/files/memory_mapped_file.h"
-#include "content/common/content_export.h"
-#include "content/public/browser/file_descriptor_info.h"
-
-namespace content {
-
-class FileDescriptorInfoImpl : public FileDescriptorInfo {
- public:
-  CONTENT_EXPORT static std::unique_ptr<FileDescriptorInfo> Create();
-
-  ~FileDescriptorInfoImpl() override;
-  void Share(int id, base::PlatformFile fd) override;
-  void ShareWithRegion(int id, base::PlatformFile fd,
-      const base::MemoryMappedFile::Region& region) override;
-  void Transfer(int id, base::ScopedFD fd) override;
-  const base::FileHandleMappingVector& GetMapping() const override;
-  std::unique_ptr<base::FileHandleMappingVector> GetMappingWithIDAdjustment(
-      int delta) const override;
-  base::PlatformFile GetFDAt(size_t i) const override;
-  int GetIDAt(size_t i) const override;
-  const base::MemoryMappedFile::Region& GetRegionAt(size_t i) const override;
-  size_t GetMappingSize() const override;
-  bool OwnsFD(base::PlatformFile file) const override;
-  base::ScopedFD ReleaseFD(base::PlatformFile file) override;
-
- private:
-  FileDescriptorInfoImpl();
-
-  void AddToMapping(int id, base::PlatformFile fd,
-      const base::MemoryMappedFile::Region& region);
-  bool HasID(int id) const;
-  base::FileHandleMappingVector mapping_;
-  // Maps the ID of a FD to the region to use for that FD, the whole file if not
-  // in the map.
-  std::map<int, base::MemoryMappedFile::Region> ids_to_regions_;
-  std::vector<base::ScopedFD> owned_descriptors_;
-};
-}
-
-#endif  // CONTENT_BROWSER_FILE_DESCRIPTOR_INFO_IMPL_H_