Pass in bad proxy to NotifyProxyFallback and not the successful one.

This cl fixes a bug which was causing the final successful proxy
to be passed to NotifyProxyFallback rather than the proxy for which
fallback happened.

BUG=395769

Review URL: https://codereview.chromium.org/556933003

Cr-Commit-Position: refs/heads/master@{#294039}

net/proxy/proxy_service.cc

@@ -1249,8 +1249,10 @@ void ProxyService::ReportSuccess(const ProxyInfo& result,
     if (existing == proxy_retry_info_.end()) {
       proxy_retry_info_[iter->first] = iter->second;
       if (network_delegate) {
+        const ProxyServer& bad_proxy =
+            ProxyServer::FromURI(iter->first, ProxyServer::SCHEME_HTTP);
         const ProxyRetryInfo& proxy_retry_info = iter->second;
-        network_delegate->NotifyProxyFallback(result.proxy_server(),
+        network_delegate->NotifyProxyFallback(bad_proxy,
                                               proxy_retry_info.net_error);
       }
     }

net/proxy/proxy_service_unittest.cc

@@ -962,7 +962,7 @@ TEST_F(ProxyServiceTest, ProxyFallback) {
   // first proxy as bad.
   TestProxyFallbackNetworkDelegate test_delegate;
   service.ReportSuccess(info, &test_delegate);
-  EXPECT_EQ(info.proxy_server(), test_delegate.proxy_server());
+  EXPECT_EQ("foopy1:8080", test_delegate.proxy_server().ToURI());
   EXPECT_EQ(net::ERR_PROXY_CONNECTION_FAILED,
             test_delegate.proxy_fallback_net_error());