Retry proxies which were cached as bad before giving up....

net/proxy/proxy_list.cc

 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/proxy/proxy_list.h"
 
 #include "base/logging.h"
 #include "base/string_tokenizer.h"
 #include "base/time.h"
 
@@ skipping 13 matching lines @@
       proxies_.push_back(uri);
   }
 }
 
 void ProxyList::SetSingleProxyServer(const ProxyServer& proxy_server) {
   proxies_.clear();
   if (proxy_server.is_valid())
     proxies_.push_back(proxy_server);
 }
 
-void ProxyList::RemoveBadProxies(const ProxyRetryInfoMap& proxy_retry_info) {
-  std::vector<ProxyServer> new_proxy_list;
+void ProxyList::DeprioritizeBadProxies(
+    const ProxyRetryInfoMap& proxy_retry_info) {
+  // Partition the proxy list in two:
+  //   (1) the known bad proxies
+  //   (2) everything else
+  std::vector<ProxyServer> good_proxies;
+  std::vector<ProxyServer> bad_proxies;
+
   std::vector<ProxyServer>::const_iterator iter = proxies_.begin();
   for (; iter != proxies_.end(); ++iter) {
     ProxyRetryInfoMap::const_iterator bad_proxy =
         proxy_retry_info.find(iter->ToURI());
     if (bad_proxy != proxy_retry_info.end()) {
       // This proxy is bad. Check if it's time to retry.
       if (bad_proxy->second.bad_until >= TimeTicks::Now()) {
         // still invalid.
+        bad_proxies.push_back(*iter);
         continue;
       }
     }
-    new_proxy_list.push_back(*iter);
+    good_proxies.push_back(*iter);
   }
 
-  proxies_ = new_proxy_list;
+  // "proxies_ = good_proxies + bad_proxies"
+  proxies_.swap(good_proxies);
+  proxies_.insert(proxies_.end(), bad_proxies.begin(), bad_proxies.end());
 }
 
 void ProxyList::RemoveProxiesWithoutScheme(int scheme_bit_field) {
   for (std::vector<ProxyServer>::iterator it = proxies_.begin();
        it != proxies_.end(); ) {
     if (!(scheme_bit_field & it->scheme())) {
       it = proxies_.erase(it);
       continue;
     }
     ++it;
@@ skipping 77 matching lines @@
     }
   }
 
   // Remove this proxy from our list.
   proxies_.erase(proxies_.begin());
 
   return !proxies_.empty();
 }
 
 }  // namespace net