Remove renderer notifications of memory pressure.

content/common/memory_messages.h

-// Copyright 2015 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.
-
-// This file contains IPC messages for controlling memory pressure handling
-// in child processes for the purposes of enforcing consistent conditions
-// across memory measurements.
-
-// Multiply-included message header, no traditional include guard.
-
-#include "base/memory/memory_pressure_listener.h"
-#include "ipc/ipc_message_macros.h"
-#include "content/common/content_export.h"
-
-#undef IPC_MESSAGE_EXPORT
-#define IPC_MESSAGE_EXPORT CONTENT_EXPORT
-
-#define IPC_MESSAGE_START MemoryMsgStart
-
-IPC_ENUM_TRAITS_VALIDATE(
-    base::MemoryPressureListener::MemoryPressureLevel,
-    (value == base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_MODERATE ||
-     value == base::MemoryPressureListener::MEMORY_PRESSURE_LEVEL_CRITICAL))
-
-// Sent to all child processes to enable/disable suppressing memory pressure
-// notifications.
-IPC_MESSAGE_CONTROL1(MemoryMsg_SetPressureNotificationsSuppressed,
-                     bool /* suppressed */)
-
-// Sent to all child processes to simulate a memory pressure notification.
-IPC_MESSAGE_CONTROL1(
-    MemoryMsg_SimulatePressureNotification,
-    base::MemoryPressureListener::MemoryPressureLevel /* level */)
-
-// Sent by the browser to all child processes to indicate an actual memory
-// pressure notification.
-IPC_MESSAGE_CONTROL1(
-    MemoryMsg_PressureNotification,
-    base::MemoryPressureListener::MemoryPressureLevel /* level */)