Add .desktop file to download_file_types.asciipb

.desktop files act as shortcuts on Linux, allowing arbitrary code
execution. We should send pings for these files.

Bug: 904182
Change-Id: Ibc26141fb180e843e1ffaf3f78717a9109d2fa9a
Reviewed-on: https://chromium-review.googlesource.com/c/1344552
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#611272}
void RecordDownloadCount(DownloadCountTypes type) {
  UMA_HISTOGRAM_ENUMERATION("Download.Counts", type,
                            DOWNLOAD_COUNT_TYPES_LAST_ENTRY);
}

void RecordDownloadCount(DownloadCountTypes type) {
  UMA_HISTOGRAM_ENUMERATION("Download.Counts", type,
                            DOWNLOAD_COUNT_TYPES_LAST_ENTRY);
}
