Only mark a proxy as bad if we have confirmation that another proxy succeeded for the same request.

net/proxy/proxy_service.cc

Index: net/proxy/proxy_service.cc
diff --git a/net/proxy/proxy_service.cc b/net/proxy/proxy_service.cc
index 66bf929005ea982dc18d44460a7c21122c7eb96d..643b9be9370e2c18a7f7ece32a24d2fc09c87972 100644
--- a/net/proxy/proxy_service.cc
+++ b/net/proxy/proxy_service.cc
@@ -264,6 +264,31 @@ class ProxyConfigChangedNetLogParam : public NetLog::EventParameters {
   DISALLOW_COPY_AND_ASSIGN(ProxyConfigChangedNetLogParam);
 };
 
+class BadProxyListNetLogParam : public NetLog::EventParameters {
+ public:
+  BadProxyListNetLogParam(const ProxyRetryInfoMap& retry_info) {
+    proxy_list_.reserve(retry_info.size());
+    for (ProxyRetryInfoMap::const_iterator iter = retry_info.begin();
+         iter != retry_info.end(); ++iter) {
+      proxy_list_.push_back(iter->first);
+    }
+  }
+
+  virtual Value* ToValue() const OVERRIDE {
+    DictionaryValue* dict = new DictionaryValue();
+    ListValue* list = new ListValue();
+    for (std::vector<std::string>::const_iterator iter = proxy_list_.begin();
+         iter != proxy_list_.end(); ++iter)
+      list->Append(Value::CreateStringValue(*iter));
+    dict->Set("bad_proxy_list", list);
+    return dict;
+  }
+
+ private:
+  std::vector<std::string> proxy_list_;
+  DISALLOW_COPY_AND_ASSIGN(BadProxyListNetLogParam);
+};
+
 }  // namespace
 
 // ProxyService::PacRequest ---------------------------------------------------
@@ -715,13 +740,38 @@ int ProxyService::ReconsiderProxyAfterError(const GURL& url,
 
   // We don't have new proxy settings to try, try to fallback to the next proxy
   // in the list.
-  bool did_fallback = result->Fallback(&proxy_retry_info_);
+  bool did_fallback = result->Fallback(net_log);
 
   // Return synchronous failure if there is nothing left to fall-back to.
   // TODO(eroman): This is a yucky API, clean it up.
   return did_fallback ? OK : ERR_FAILED;
 }
 
+void ProxyService::ReportSuccess(const ProxyInfo& result) {
+  DCHECK(CalledOnValidThread());
+
+  const ProxyRetryInfoMap& new_retry_info = result.proxy_retry_info();
+  if (new_retry_info.empty())
+    return;
+
+  for (ProxyRetryInfoMap::const_iterator iter = new_retry_info.begin();
+       iter != new_retry_info.end(); ++iter) {
+    ProxyRetryInfoMap::iterator existing = proxy_retry_info_.find(iter->first);
+    if (existing == proxy_retry_info_.end())
+      proxy_retry_info_[iter->first] = iter->second;
+    else if (existing->second.bad_until < iter->second.bad_until)
+      existing->second.bad_until = iter->second.bad_until;
+  }
+  if (net_log_) {
+    net_log_->AddEntry(NetLog::TYPE_BAD_PROXY_LIST_REPORTED,
+                       base::TimeTicks::Now(),
+                       NetLog::Source(),
+                       NetLog::PHASE_NONE,
+                       make_scoped_refptr(
+                           new BadProxyListNetLogParam(new_retry_info)));
+  }
+}
+
 void ProxyService::CancelPacRequest(PacRequest* req) {
   DCHECK(CalledOnValidThread());
   DCHECK(req);