[Downloads] Retry renames after transient failures.

content/browser/download/download_file_impl.h

Index: content/browser/download/download_file_impl.h
diff --git a/content/browser/download/download_file_impl.h b/content/browser/download/download_file_impl.h
index 2ba3d8d058e27211d3eaefc32c9e177f511e67d1..bb84d79de78f636078f51ef38b209ceb72b967d0 100644
--- a/content/browser/download/download_file_impl.h
+++ b/content/browser/download/download_file_impl.h
@@ -68,7 +68,34 @@ class CONTENT_EXPORT DownloadFileImpl : virtual public DownloadFile {
   virtual DownloadInterruptReason AppendDataToFile(
       const char* data, size_t data_len);
 
+  virtual base::TimeDelta GetRetryDelayForFailedRename(int attempt_number);
+
+  virtual bool ShouldRetryFailedRename(DownloadInterruptReason reason);
+
  private:
+  friend class DownloadFileTest;
+
+  // Options for RenameWithRetryInternal.
+  enum RenameOption {
+    UNIQUIFY = 1 << 0,  // If there's already a file on disk that conflicts with
+                        // |new_path|, try to create a unique file by appending
+                        // a uniquifier.
+    ANNOTATE_WITH_SOURCE_INFORMATION = 1 << 1
+  };
+
+  // Rename file_ to |new_path|.
+  // |option| specifies additional operations to be performed during the rename.
+  //     See RenameOptions above.

[Randy Smith (Not in Mondays), 2014/06/11 18:07:29]

nit: No 's'  (IMO).

[asanka, 2014/06/12 20:02:37]

Done.

+  // |retries_left| indicates how many times to retry the operation if the
+  //     rename fails with a transient error.
+  // |time_of_first_failure| should be empty when this method is called for the
+  //     first time.

[Randy Smith (Not in Mondays), 2014/06/11 18:07:29]

If you just read the comment, you're left with the question "and what about when
I'm not calling it for the first time?"  Maybe instead "should be empty (it is
used to propagate time to first failure for internal retries)."?

[asanka, 2014/06/12 20:02:37]

Reworded.

+  void RenameWithRetryInternal(const base::FilePath& new_path,
+                               RenameOption option,
+                               int retries_left,
+                               base::TimeTicks time_of_first_failure,
+                               const RenameCompletionCallback& callback);
+
   // Send an update on our progress.
   void SendUpdate();