Shift passage of FileStream in downloads system to be by scoped_ptr<>.

content/browser/web_contents/web_drag_source_mac.mm

 // 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.
 
 #import "content/browser/web_contents/web_drag_source_mac.h"
 
 #include <sys/param.h>
 
 #include "base/bind.h"
 #include "base/file_path.h"
@@ skipping 324 matching lines @@
 
   FilePath fileName = downloadFileName_.empty() ?
       GetFileNameFromDragData(*dropData_) : downloadFileName_;
   FilePath filePath(SysNSStringToUTF8(path));
   filePath = filePath.Append(fileName);
 
   // CreateFileStreamForDrop() will call file_util::PathExists(),
   // which is blocking.  Since this operation is already blocking the
   // UI thread on OSX, it should be reasonable to let it happen.
   base::ThreadRestrictions::ScopedAllowIO allowIO;
-  FileStream* fileStream =
+  scoped_ptr<FileStream> fileStream(
       drag_download_util::CreateFileStreamForDrop(
-          &filePath, content::GetContentClient()->browser()->GetNetLog());
-  if (!fileStream)
+          &filePath, content::GetContentClient()->browser()->GetNetLog()));
+  if (!fileStream.get())
     return nil;
 
   if (downloadURL_.is_valid()) {
     scoped_refptr<DragDownloadFile> dragFileDownloader(new DragDownloadFile(
         filePath,
-        linked_ptr<net::FileStream>(fileStream),
+        fileStream.Pass(),
         downloadURL_,
         content::Referrer(contents_->GetURL(), dropData_->referrer_policy),
         contents_->GetEncoding(),
         contents_));
 
     // The finalizer will take care of closing and deletion.
     dragFileDownloader->Start(
         new drag_download_util::PromiseFileFinalizer(dragFileDownloader));
   } else {
     // The writer will take care of closing and deletion.
@@ skipping 99 matching lines @@
 - (NSImage*)dragImage {
   if (dragImage_)
     return dragImage_;
 
   // Default to returning a generic image.
   return content::GetContentClient()->GetNativeImageNamed(
       IDR_DEFAULT_FAVICON).ToNSImage();
 }
 
 @end  // @implementation WebDragSource (Private)