MemoryPressure: sends the signal to the renderer.

content/common/memory_pressure_messages.h

Index: content/common/memory_pressure_messages.h
diff --git a/content/common/memory_pressure_messages.h b/content/common/memory_pressure_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..6dad847036053e6821dc09008c804eb6b1c4c952
--- /dev/null
+++ b/content/common/memory_pressure_messages.h
@@ -0,0 +1,20 @@
+// Copyright (c) 2013 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.
+
+// Message definition file, included multiple times, hence no include guard.
+
+#include "base/memory/memory_pressure_listener.h"
+#include "ipc/ipc_message_macros.h"
+#include "ipc/ipc_param_traits.h"
+
+#define IPC_MESSAGE_START MemoryPressureMsgStart
+
+// Argument structures used in messages
+
+IPC_ENUM_TRAITS(base::MemoryPressureListener::MemoryPressureLevel)
+
+// Message sent from the browser to the renderer.
+
+IPC_MESSAGE_CONTROL1(MemoryPressureMsg_MemoryPressure,
+                     base::MemoryPressureListener::MemoryPressureLevel)