NTPSnippets: Set MaxRetriesOn5xx only for interactive requests.

components/ntp_snippets/remote/ntp_snippets_fetcher.cc

Index: components/ntp_snippets/remote/ntp_snippets_fetcher.cc
diff --git a/components/ntp_snippets/remote/ntp_snippets_fetcher.cc b/components/ntp_snippets/remote/ntp_snippets_fetcher.cc
index 62236a8a375cab50981b1a7798b0ce55f963798c..94b5183ea1823f040921136dcabcd576ea1a777a 100644
--- a/components/ntp_snippets/remote/ntp_snippets_fetcher.cc
+++ b/components/ntp_snippets/remote/ntp_snippets_fetcher.cc
@@ -812,8 +812,14 @@ NTPSnippetsFetcher::RequestBuilder::BuildURLFetcher(
 
   // Fetchers are sometimes cancelled because a network change was detected.
   url_fetcher->SetAutomaticallyRetryOnNetworkChanges(3);
-  // Try to make fetching the files bit more robust even with poor connection.
-  url_fetcher->SetMaxRetriesOn5xx(3);
+  if (params_.interactive_request) {
+    // Try to make fetching the files bit more robust even with poor connection.
+    url_fetcher->SetMaxRetriesOn5xx(2);
+  } else {
+    // Don't retry immediately if a scheduled fetch fails.
+    // TODO(fhorschig): back off for 1h (+1h jitter) and then retry.

[Marc Treib, 2016/12/06 16:06:56]

I'm not convinced we actually want to do this :)
Maybe better put this discussion in the bug?

[fhorschig, 2016/12/08 10:20:58]

Done already. I removed this comment for now as I won't submit this CL anyway
until I know if it is actually wanted behavior.

+    url_fetcher->SetMaxRetriesOn5xx(0);

[Marc Treib, 2016/12/06 16:06:56]

As discussed offline: Should we introduce a variation parameter to control this?

[fhorschig, 2016/12/08 10:20:58]

Done.

+  }
   return url_fetcher;
 }