Turn FileDescriptorInfo a collection class

content/public/browser/file_descriptor_info.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_PUBLIC_BROWSER_FILE_DESCRIPTOR_INFO_H_
 #define CONTENT_PUBLIC_BROWSER_FILE_DESCRIPTOR_INFO_H_
 
-#include "base/file_descriptor_posix.h"
+#include "base/files/file.h"
+#include "base/memory/scoped_vector.h"
+#include "base/process/launch.h"
+#include "content/common/content_export.h"
 
 namespace content {
 
-// This struct is used when passing files that should be mapped in a process
-// that is been created and allows to associate that file with a specific ID.
-// It also provides a way to know if the actual file descriptor should be
-// closed with the FileDescriptor.auto_close field.
+// FileDescriptorInfo is a collection of file descriptors which is

[jam, 2014/09/23 05:16:09]

this doesn't conform to the content api
http://www.chromium.org/developers/content-module/content-api

+// needed to launch a process. You should to tell FileDescriptorInfo
+// which FD should be closed and which isn't so that it can take care
+// of the lifetime of FDs.
+//
+// See base/process/launcher.h for more details about launching a
+// process.
+class CONTENT_EXPORT FileDescriptorInfo {
+ public:
+  FileDescriptorInfo();
+  ~FileDescriptorInfo();
 
-struct FileDescriptorInfo {
-  FileDescriptorInfo(int id, const base::FileDescriptor& file_descriptor)
-      : id(id),
-        fd(file_descriptor) {
-  }
+  // Add and FD associated with an ID, without delegating the ownerhip
+  // of ID.
+  void Share(int id, base::PlatformFile fd);
+  // Add an FD associated with an ID, passing the FD ownership to
+  // FileDescriptorInfo.
+  void Transfer(int id, base::ScopedFD fd);
+  // Just delegating a lifetime of an FD. This is needed as some FDs
+  // are transferred to another process without key mapping.
+  void TransferWithoutMapping(base::ScopedFD fd);
+  // A vecotr-backed map from registered ID-FD pair.
+  const base::FileHandleMappingVector& GetMapping() const;
+  // A GetMapping() variant what adjusts the ID value by |delta|.
+  // Some environments need this trick.
+  base::FileHandleMappingVector GetMappingWithIDAdjustment(int delta) const;
 
-  int id;
-  base::FileDescriptor fd;
+  // API for iterating registerd ID-FD pair.
+  base::PlatformFile GetFDAt(size_t i) const;
+  int GetIDAt(size_t i) const;
+  size_t GetMappingSize() const { return mapping_.size(); }
+
+ private:
+  void AddToMapping(int id, base::PlatformFile fd);
+
+  base::FileHandleMappingVector mapping_;
+  ScopedVector<base::ScopedFD> owned_descriptors_;
 };
 
 }
 
 #endif  // CONTENT_PUBLIC_BROWSER_FILE_DESCRIPTOR_INFO_H_