Add MemoryCoordinator

components/memory_coordinator/child/child_memory_coordinator_impl.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/child/child_memory_coordinator_impl.h"
 
+#include "components/memory_coordinator/public/interfaces/memory_coordinator.mojom.h"
+
 namespace memory_coordinator {
 
-ChildMemoryCoordinatorImpl::ChildMemoryCoordinatorImpl(
-      mojo::InterfaceRequest<mojom::ChildMemoryCoordinator> request,
-      scoped_refptr<ClientList> clients)
-    : binding_(this, std::move(request)),
-      clients_(clients) {}
+ChildMemoryCoordinatorImpl::ChildMemoryCoordinatorImpl()
+    : binding_(this), clients_(new ClientList) {}
 
 ChildMemoryCoordinatorImpl::~ChildMemoryCoordinatorImpl() {}
 
+void ChildMemoryCoordinatorImpl::Bind(
+    mojom::ChildMemoryCoordinatorRequest request) {
+  binding_.Bind(std::move(request));

[dcheng, 2016/07/08 07:10:35]

I think it is somewhat unusual that we have a persistent object (scoped to
lifetime of RenderThreadImpl) that only accepts one binding request. Logically,
this is OK, since the browser process should only ever connect once, but it
feels a bit weird. I am going to ask chromium-mojo about best practices for
this.

[bashi, 2016/07/08 07:32:39]

Yeah.. Actually, in PS#5 I didn't use this pattern (I guess PS#5 is a usual
way). The reason I changed the pattern is that the browser needs to have
RenderProcessHost::GetID() -> ChildMemoryCoordinatorPtr mappings so that the
central MemoryCoordinator can use the logic in TabManager (which uses
RenderProcessHost and old IPC) to dispatch memory pressure notification to
renderers. I intentionally dropped the mappings from this CL to make this CL
simple, but the next CL would add the mappings. I'm happy to change this if
there is a workaround.

+}
+
+void ChildMemoryCoordinatorImpl::RegisterClient(
+    MemoryCoordinatorClient* client) {
+  clients_->AddObserver(client);
+}
+
+void ChildMemoryCoordinatorImpl::UnregisterClient(
+    MemoryCoordinatorClient* client) {
+  clients_->RemoveObserver(client);
+}
+
 void ChildMemoryCoordinatorImpl::OnStateChange(mojom::MemoryState state) {
+  state_ = state;
   clients_->Notify(FROM_HERE, &MemoryCoordinatorClient::OnMemoryStateChange,
                    state);
 }
 
+void ChildMemoryCoordinatorImpl::GetCurrentStateForTesting(
+    const GetCurrentStateForTestingCallback& callback) {
+  callback.Run(state_);
+}
+
 }  // namespace memory_coordinator