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 fe4e602c479933382dcec440de37772a24a674bd..8f33c8219b670f414b6b469b7c8687e6714a46ab 100644
--- a/chrome/browser/download/download_manager.h
+++ b/chrome/browser/download/download_manager.h
@@ -87,7 +87,9 @@ 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() {}
@@ -324,7 +326,7 @@ 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);
 
   // Called on the UI thread once the DownloadManager has determined whether the
   // suggested file path exists.