Add MemoryCoordinator

components/memory_coordinator/browser/memory_state_notifier.cc

+// Copyright 2016 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 "components/memory_coordinator/browser/memory_state_notifier.h"
+
+#include "base/bind.h"
+
+namespace memory_coordinator {
+
+MemoryStateNotifier::MemoryStateNotifier() {}
+
+MemoryStateNotifier::~MemoryStateNotifier() {}
+
+void MemoryStateNotifier::Notify(mojom::MemoryState state) {
+  for (auto& pair : children_) {
+    pair.second->OnStateChange(state);
+  }
+}
+
+void MemoryStateNotifier::IterateChildren(const IterateCallback& callback) {
+  for (auto& pair : children_) {
+    callback.Run(pair.second);
+  }
+}
+
+void MemoryStateNotifier::AddChild(mojom::ChildMemoryCoordinatorPtr child) {
+  int id = GetNextId();
+  children_[id] = std::move(child);
+  children_[id].set_connection_error_handler(base::Bind(
+      &MemoryStateNotifier::RemoveChild, base::Unretained(this), id));

[haraken, 2016/06/27 11:16:00]

I'm not sure if the ID system is the best way to implement this. I'll defer the
review to Chromium's experts.

[chrisha, 2016/06/27 20:35:30]

I don't see any problem with this, but you could also just use a std::set and
pass around the raw pointer to the child?

[bashi, 2016/06/27 22:40:23]

Yes. I'd just prefer using IDs but raw pointers should work.

+}
+
+int MemoryStateNotifier::GetNextId() {
+  return ++next_id_;
+}
+
+void MemoryStateNotifier::RemoveChild(int id) {
+  children_.erase(id);
+}
+
+}  // namespace memory_coordinator