Shut down DownloadProtectionService first

While the comment says "Must shut down last", there's no clear reason
why this would be needed. So move it first to see if there's a subtle
reason it should be last.

Change-Id: I8e778d100aeeba15d88c22e907cb369787e601e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2050677
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Auto-Submit: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#741133}

chrome/browser/safe_browsing/services_delegate_desktop.cc

@@ -109,6 +109,9 @@ void ServicesDelegateDesktop::SetDatabaseManagerForTest(
 
 void ServicesDelegateDesktop::ShutdownServices() {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  download_service_.reset();
+
   // The IO thread is going away, so make sure the ClientSideDetectionService
   // dtor executes now since it may call the dtor of URLFetcher which relies
   // on it.
@@ -121,9 +124,6 @@ void ServicesDelegateDesktop::ShutdownServices() {
   binary_upload_service_map_.clear();
 
   ServicesDelegate::ShutdownServices();
-
-  // Must shut down last.
-  download_service_.reset();
 }
 
 void ServicesDelegateDesktop::RefreshState(bool enable) {