Re-reland: Add MemoryCoordinator

components/memory_coordinator/child/child_memory_coordinator_impl.cc

Index: components/memory_coordinator/child/child_memory_coordinator_impl.cc
diff --git a/components/memory_coordinator/child/child_memory_coordinator_impl.cc b/components/memory_coordinator/child/child_memory_coordinator_impl.cc
index 75889ed43f66e6463c0e9b3dc0ed578ca745b85b..3598945c1af47104bf9c59d58d2ad618ee2abd89 100644
--- a/components/memory_coordinator/child/child_memory_coordinator_impl.cc
+++ b/components/memory_coordinator/child/child_memory_coordinator_impl.cc
@@ -7,12 +7,23 @@
 namespace memory_coordinator {
 
 ChildMemoryCoordinatorImpl::ChildMemoryCoordinatorImpl(
-      mojo::InterfaceRequest<mojom::ChildMemoryCoordinator> request,
-      scoped_refptr<ClientList> clients)
-    : binding_(this, std::move(request)),
-      clients_(clients) {}
+    mojom::MemoryCoordinatorHandlePtr parent)
+    : binding_(this), clients_(new ClientList), parent_(std::move(parent)) {
+  parent_->AddChild(binding_.CreateInterfacePtrAndBind());
+}
+
+ChildMemoryCoordinatorImpl::~ChildMemoryCoordinatorImpl() {
+}
 
-ChildMemoryCoordinatorImpl::~ChildMemoryCoordinatorImpl() {}
+void ChildMemoryCoordinatorImpl::RegisterClient(
+    MemoryCoordinatorClient* client) {
+  clients_->AddObserver(client);
+}
+
+void ChildMemoryCoordinatorImpl::UnregisterClient(
+    MemoryCoordinatorClient* client) {
+  clients_->RemoveObserver(client);
+}
 
 void ChildMemoryCoordinatorImpl::OnStateChange(mojom::MemoryState state) {
   clients_->Notify(FROM_HERE, &MemoryCoordinatorClient::OnMemoryStateChange,