Replace the DownloadFileManager with direct ownership

content/browser/download/download_item_impl_delegate.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_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_DELEGATE_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_DELEGATE_H_
 
 #include "base/file_path.h"
 #include "content/common/content_export.h"
 
 class DownloadItemImpl;
 
 namespace content {
 class BrowserContext;
 }
 
 // Delegate for operations that a DownloadItemImpl can't do for itself.
 // The base implementation of this class does nothing (returning false
 // on predicates) so interfaces not of interest to a derived class may
 // be left unimplemented.
 class CONTENT_EXPORT DownloadItemImplDelegate {
  public:
   DownloadItemImplDelegate();
   virtual ~DownloadItemImplDelegate();
 
   // Used for catching use-after-free errors.
   void Attach();
   void Detach();
 
-  // Tests if a file type should be opened automatically.
-  virtual bool ShouldOpenFileBasedOnExtension(const FilePath& path);
+  // Start the delegate's portion of the download; called when the
+  // download item is ready for the delegate to take over.
+  // Pure virtual because if the delegate doesn't do something the
+  // DownloadItemImpl is dead in the water.
+  // TODO(rdsmith): The machinery of running the download should be
+  // moved into the DownloadItem, and this should be changed into
+  // a probe as to whether to start and if not, provide a callback
+  // to call when it's time to start.
+  virtual void DelegateStart(DownloadItemImpl* download) = 0;
 
   // Allows the delegate to override the opening of a download. If it returns
   // true then it's reponsible for opening the item.
   virtual bool ShouldOpenDownload(DownloadItemImpl* download);
 
+  // Tests if a file type should be opened automatically.
+  virtual bool ShouldOpenFileBasedOnExtension(const FilePath& path);
+
   // Checks whether a downloaded file still exists and updates the
   // file's state if the file is already removed.
   // The check may or may not result in a later asynchronous call
   // to OnDownloadedFileRemoved().
   virtual void CheckForFileRemoval(DownloadItemImpl* download_item);
 
   // If all pre-requisites have been met, complete download processing.
   // TODO(rdsmith): Move into DownloadItem.
   virtual void MaybeCompleteDownload(DownloadItemImpl* download);
 
@@ skipping 14 matching lines @@
   virtual void AssertStateConsistent(DownloadItemImpl* download) const;
 
  private:
   // For "Outlives attached DownloadItemImpl" invariant assertion.
   int count_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadItemImplDelegate);
 };
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_IMPL_DELEGATE_H_