CrOS - Fix crash in file browser the second time you save a file

We were not cleaning up callbacks after the dialog closed, so it crashed with a stale "params" pointer (user data for the callback).

BUG=chromium-os:15650
TEST=Right-click Save As an image.  Right-click Save As the same image again.  Verify Chrome does not crash.

Review URL: http://codereview.chromium.org/7064037

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@86466 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/file_manager_dialogs.cc

@@ -86,6 +86,7 @@ void FileManagerDialog::ListenerDestroyed() {
 
 void FileManagerDialog::ExtensionDialogIsClosing(ExtensionDialog* dialog) {
   owner_window_ = NULL;
+  FileDialogFunction::Callback::Remove(tab_id_);
 }
 
 void FileManagerDialog::SelectFileImpl(