Architecture for cross-process memory notification suppressing

content/child/memory/child_memory_message_filter.cc

Index: content/child/memory/child_memory_message_filter.cc
diff --git a/content/child/memory/child_memory_message_filter.cc b/content/child/memory/child_memory_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2cbe5d4b9e72d9545bc0efe7b73edbc750563b55
--- /dev/null
+++ b/content/child/memory/child_memory_message_filter.cc
@@ -0,0 +1,46 @@
+// 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.
+
+#include "content/child/memory/child_memory_message_filter.h"
+
+#include "base/memory/memory_pressure_listener.h"
+#include "content/common/memory_messages.h"
+#include "ipc/ipc_channel.h"
+
+namespace content {
+namespace memory {
+
+ChildMemoryMessageFilter::ChildMemoryMessageFilter() : sender_(nullptr) {}
+
+ChildMemoryMessageFilter::~ChildMemoryMessageFilter() {}
+
+void ChildMemoryMessageFilter::OnFilterAdded(IPC::Sender* sender) {
+  DCHECK(sender_ == nullptr);
+  sender_ = sender;
+}
+
+void ChildMemoryMessageFilter::OnFilterRemoved() {
+  DCHECK(sender_ != nullptr);
+  sender_ = nullptr;
+}
+
+bool ChildMemoryMessageFilter::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(ChildMemoryMessageFilter, message)
+    IPC_MESSAGE_HANDLER(MemoryMsg_SetPressureNotificationsSuppressed,
+                        OnSetPressureNotificationsSuppressed)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void ChildMemoryMessageFilter::OnSetPressureNotificationsSuppressed(
+    bool suppressed) {
+  // Enable/disable suppressing memory notifications in the child process.
+  base::MemoryPressureListener::SetNotificationsSuppressed(suppressed);
+  sender_->Send(new MemoryHostMsg_SetPressureNotificationsSuppressedAck);
+}
+
+}  // namespace memory
+}  // namespace content