Introduce net::HttpServerPropertiesManager to manage server-specific properties.

net/url_request/url_request_context_storage.cc

Index: net/url_request/url_request_context_storage.cc
===================================================================
--- net/url_request/url_request_context_storage.cc	(revision 99284)
+++ net/url_request/url_request_context_storage.cc	(working copy)
@@ -73,6 +73,12 @@
   proxy_service_.reset(proxy_service);
 }
 
+void URLRequestContextStorage::set_spdy_config_service(
+    SpdyConfigService* spdy_config_service) {
+  context_->set_spdy_config_service(spdy_config_service);
+  spdy_config_service_ = spdy_config_service;
+}
+
 void URLRequestContextStorage::set_ssl_config_service(
     SSLConfigService* ssl_config_service) {
   context_->set_ssl_config_service(ssl_config_service);