[HttpNetworkSession] Flush socket pools on low memory notification.

net/http/http_network_session.cc

 // Copyright (c) 2012 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/http/http_network_session.h"
 
 #include <utility>
 
 #include "base/atomic_sequence_num.h"
 #include "base/compiler_specific.h"
@@ skipping 222 matching lines @@
     AlternateProtocol alternate =
         AlternateProtocolFromNextProto(kProtoQUIC1SPDY3);
     enabled_protocols_[alternate - ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION] =
         true;
   }
 
   next_protos_.push_back(kProtoHTTP11);
 
   http_server_properties_->SetMaxServerConfigsStoredInProperties(
       params.quic_max_server_configs_stored_in_properties);
+
+  memory_pressure_listener_.reset(new base::MemoryPressureListener(base::Bind(
+      &HttpNetworkSession::OnMemoryPressure, base::Unretained(this))));
 }
 
 HttpNetworkSession::~HttpNetworkSession() {
   STLDeleteElements(&response_drainers_);
   spdy_session_pool_.CloseAllSessions();
 }
 
 void HttpNetworkSession::AddResponseDrainer(HttpResponseBodyDrainer* drainer) {
   DCHECK(!ContainsKey(response_drainers_, drainer));
   response_drainers_.insert(drainer);
@@ skipping 142 matching lines @@
       return normal_socket_pool_manager_.get();
     case WEBSOCKET_SOCKET_POOL:
       return websocket_socket_pool_manager_.get();
     default:
       NOTREACHED();
       break;
   }
   return NULL;
 }
 
+void HttpNetworkSession::OnMemoryPressure(
+    base::MemoryPressureListener::MemoryPressureLevel memory_pressure_level) {
+  switch (memory_pressure_level) {
+    case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_NONE:
+      break;
+    case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE:
+    case base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL:
+      CloseIdleConnections();
+      break;
+  }
+}
+
 }  // namespace net