Android: Get rid of extra dup()s on launching child processes

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/files/file.h"
 #include "base/process/launch.h"
 
@@ skipping 23 matching lines @@
 
   // A GetMapping() variant what adjusts the ID value by |delta|.
   // Some environments need this trick.
   virtual base::FileHandleMappingVector GetMappingWithIDAdjustment(
       int delta) const = 0;
 
   // API for iterating registered ID-FD pairs.
   virtual base::PlatformFile GetFDAt(size_t i) const = 0;
   virtual int GetIDAt(size_t i) const = 0;
   virtual size_t GetMappingSize() const = 0;
+
+  // True if |this| has an ownership of |file|.
+  virtual bool OwnsFD(base::PlatformFile file) const = 0;
+  // Assuming |OwnsFD(file)|, release the ownership.
+  virtual base::ScopedFD ReleaseFD(base::PlatformFile file) = 0;
 };
 
 }
 
 #endif  // CONTENT_PUBLIC_BROWSER_FILE_DESCRIPTOR_INFO_H_