net: Update FileStream to use base::File instead of PlatformFile.

base/android/content_uri_utils.h

 // Copyright 2013 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_ANDROID_CONTENT_URI_UTILS_H_
 #define BASE_ANDROID_CONTENT_URI_UTILS_H_
 
 #include <jni.h>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/files/file.h"
 #include "base/files/file_path.h"
 
 namespace base {
 
 bool RegisterContentUriUtils(JNIEnv* env);
 
 // Opens a content uri for read and returns the file descriptor to the caller.
 // Returns -1 if the uri is invalid.
-BASE_EXPORT int OpenContentUriForRead(const FilePath& content_uri);
+BASE_EXPORT File OpenContentUriForRead(const FilePath& content_uri);
 
 // Check whether a content uri exists.
 BASE_EXPORT bool ContentUriExists(const FilePath& content_uri);
 
 }  // namespace base
 
 #endif  // BASE_ANDROID_CONTENT_URI_UTILS_H_