Add a QUIC proxy server to the list of QUIC servers supported at start up

net/base/proxy_delegate.h

Index: net/base/proxy_delegate.h
diff --git a/net/base/proxy_delegate.h b/net/base/proxy_delegate.h
index fd50b20b6d015dc8d6056d6bc7813e8d0af50ad7..d68a26f624cd346e488c437cc87d4d2ef19dec55 100644
--- a/net/base/proxy_delegate.h
+++ b/net/base/proxy_delegate.h
@@ -83,6 +83,11 @@ class NET_EXPORT ProxyDelegate {
   virtual void OnAlternativeProxyBroken(
       const ProxyServer& alternative_proxy_server) = 0;
 
+  // Returns the QUIC proxy server that is expected to be used in the
+  // recent future. May return an invalid proxy server if no valid QUIC proxy
+  // server is available.
+  virtual ProxyServer GetQuicSupportedProxyServerAtStartUp() const = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ProxyDelegate);
 };