Trigger data reduction proxy unreachable message via on proxy fall back.

chrome/browser/net/chrome_network_delegate.cc

Index: chrome/browser/net/chrome_network_delegate.cc
diff --git a/chrome/browser/net/chrome_network_delegate.cc b/chrome/browser/net/chrome_network_delegate.cc
index 42b7463c0cfd528433de1873ef389e1f186f6a0d..d330dfb76551f63d14190796d4d858958be1d850 100644
--- a/chrome/browser/net/chrome_network_delegate.cc
+++ b/chrome/browser/net/chrome_network_delegate.cc
@@ -458,7 +458,7 @@ void ChromeNetworkDelegate::OnResolveProxy(
 void ChromeNetworkDelegate::OnProxyFallback(const net::ProxyServer& bad_proxy,
                                             int net_error) {
   if (data_reduction_proxy_usage_stats_) {
-    data_reduction_proxy_usage_stats_->RecordBypassEventHistograms(
+    data_reduction_proxy_usage_stats_->OnProxyFallback(
         bad_proxy, net_error);
   }
 }