Re-land: Defer SpdySession destruction to support closing writes

net/http/http_stream_factory_impl_request.cc

Index: net/http/http_stream_factory_impl_request.cc
diff --git a/net/http/http_stream_factory_impl_request.cc b/net/http/http_stream_factory_impl_request.cc
index 38bc03c6bfb917d2b8407576f61a2617cbf6e3ec..b4618926a05c761bd8c715c987c6f373b6b9766f 100644
--- a/net/http/http_stream_factory_impl_request.cc
+++ b/net/http/http_stream_factory_impl_request.cc
@@ -292,6 +292,13 @@ HttpStreamFactoryImpl::Request::RemoveRequestFromHttpPipeliningRequestMap() {
   }
 }
 
+// TODO(jgraettinger): Currently, HttpStreamFactoryImpl::Job notifies a
+// Request that the session is ready, which in turn notifies it's delegate,
+// and then it notifies HttpStreamFactoryImpl so that /other/ requests may
+// be woken, but only if the spdy_session is still okay. This is tough to grok.
+// Instead, see if Job can notify HttpStreamFactoryImpl only, and have one
+// path for notifying any requests waiting for the session (including the
+// request which spawned it).
 void HttpStreamFactoryImpl::Request::OnNewSpdySessionReady(
     Job* job,
     scoped_ptr<HttpStream> stream,
@@ -334,7 +341,7 @@ void HttpStreamFactoryImpl::Request::OnNewSpdySessionReady(
                              stream.release());
   }
   // |this| may be deleted after this point.
-  if (spdy_session) {
+  if (spdy_session && spdy_session->IsAvailable()) {
     factory->OnNewSpdySessionReady(spdy_session,
                                    direct,
                                    used_ssl_config,