Files required by a service now listed in manifest.

base/file_descriptor_store.h

+// 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.
+
+#ifndef BASE_FILE_DESCRIPTOR_STORE_H_
+#define BASE_FILE_DESCRIPTOR_STORE_H_
+
+#include <map>
+#include <string>
+
+#include "base/files/memory_mapped_file.h"
+#include "base/files/scoped_file.h"
+#include "base/macros.h"
+
+namespace base {
+
+// The file descriptor store is used to associate file descriptors with keys
+// that must be unique.
+// It is used to share file descriptors from a process to its child.
+class BASE_EXPORT FileDescriptorStore {
+ public:
+  struct Descriptor {
+    Descriptor(const std::string& key, base::ScopedFD fd);
+    Descriptor(const std::string& key,
+               base::ScopedFD fd,
+               base::MemoryMappedFile::Region region);
+    Descriptor(Descriptor&& other);
+    ~Descriptor();
+
+    Descriptor& operator=(Descriptor&& other) = default;
+
+    // Globally unique key.
+    std::string key;
+    // Actual FD.
+    base::ScopedFD fd;
+    // Optional region, defaults to kWholeFile.
+    base::MemoryMappedFile::Region region;
+  };
+  using Mapping = std::map<std::string, Descriptor>;
+
+  // Returns the singleton instance of FileDescriptorStore.
+  static FileDescriptorStore& GetInstance();
+
+  // Gets a descriptor given a key and also populates |region| if non null.

[dcheng, 2017/02/15 08:05:27]

Nit: remove optional-ness of |region|

[Jay Civelli, 2017/02/15 19:53:47]

Done.

+  // It is a fatal error if the key is not known.
+  base::ScopedFD TakeFD(const std::string& key,
+                        base::MemoryMappedFile::Region* region);
+
+  // Gets a descriptor given a key. Returns an empty ScopedFD on error.
+  base::ScopedFD MaybeTakeFD(const std::string& key,
+                             base::MemoryMappedFile::Region* region);
+
+  // Sets the descriptor for the given |key|. This sets the region associated
+  // with |key| to kWholeFile.
+  void Set(const std::string& key, base::ScopedFD fd);
+
+  // Sets the descriptor and |region| for the given |key|.
+  void Set(const std::string& key,
+           base::ScopedFD fd,
+           base::MemoryMappedFile::Region region);
+
+ private:
+  FileDescriptorStore();
+  ~FileDescriptorStore();
+
+  Mapping descriptors_;
+
+  DISALLOW_COPY_AND_ASSIGN(FileDescriptorStore);
+};
+
+}  // namespace base
+
+#endif  // BASE_FILE_DESCRIPTOR_STORE_H_