[downloads] Move platform specific code out of DownloadTargetDeterminer.

chrome/browser/download/download_file_picker.cc

Index: chrome/browser/download/download_file_picker.cc
diff --git a/chrome/browser/download/download_file_picker.cc b/chrome/browser/download/download_file_picker.cc
index 1e625ba63eee4360d3f5e37f5310d53166862580..f12b144d2d3fb2501d668270b54bc59e76fc3451 100644
--- a/chrome/browser/download/download_file_picker.cc
+++ b/chrome/browser/download/download_file_picker.cc
@@ -96,7 +96,10 @@ DownloadFilePicker::~DownloadFilePicker() {
 void DownloadFilePicker::OnFileSelected(const base::FilePath& path) {
   if (should_record_file_picker_result_)
     RecordFilePickerResult(suggested_path_, path);
-  file_selected_callback_.Run(path);
+  file_selected_callback_.Run(path.empty()
+                                  ? DownloadConfirmationResult::CANCELED
+                                  : DownloadConfirmationResult::CONFIRMED,
+                              path);
   delete this;
 }