When the download folder does not exist, change the download folder to a user's "Downloads"

chrome/browser/download/download_manager.h

Index: chrome/browser/download/download_manager.h
diff --git a/chrome/browser/download/download_manager.h b/chrome/browser/download/download_manager.h
index e3ffd0291865a7b046fa79421abb3821db9695f3..0d2e560e28c1c58f7705247cf3719a897bbc74a5 100644
--- a/chrome/browser/download/download_manager.h
+++ b/chrome/browser/download/download_manager.h
@@ -86,7 +86,9 @@ class DownloadManager
     // Called immediately after the DownloadManager puts up a select file
     // dialog.
     // |id| indicates which download opened the dialog.
-    virtual void SelectFileDialogDisplayed(int32 id) {}
+    // |suggested_path| indicates the path suggested in the dialog.
+    virtual void SelectFileDialogDisplayed(
+        int32 id, const FilePath& suggested_path) {}
 
    protected:
     virtual ~Observer() {}
@@ -306,7 +308,8 @@ class DownloadManager
   // stalls from interacting with the file system.
   void CheckIfSuggestedPathExists(int32 download_id,
                                   DownloadStateInfo state,
-                                  const FilePath& default_path);
+                                  const FilePath& download_save_dir,
+                                  const FilePath& default_download_dir);
 
   // Called on the UI thread once the DownloadManager has determined whether the
   // suggested file path exists.