Add MemoryCoordinator

components/memory_coordinator/browser/memory_coordinator.h

+// 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.
+
+#ifndef COMPONENTS_MEMORY_COORDINATOR_BROWSER_MEMORY_COORDINATOR_H_
+#define COMPONENTS_MEMORY_COORDINATOR_BROWSER_MEMORY_COORDINATOR_H_
+
+#include "components/memory_coordinator/public/interfaces/memory_coordinator.mojom.h"
+#include "mojo/public/cpp/bindings/binding.h"
+
+namespace memory_coordinator {
+
+class MemoryCoordinatorHandleImpl;
+
+// MemoryCoordinator is responsible for the whole memory management accross the
+// browser and child proceeses. It will dispatch memory events to its clients
+// and child processes based on its best knowledge of the memory usage.
+class MemoryCoordinator {
+ public:
+  MemoryCoordinator();
+  ~MemoryCoordinator();
+
+  void CreateHandle(int id, mojom::MemoryCoordinatorHandleRequest request);

[dcheng, 2016/07/12 05:20:28]

Nit: please call this rph_id or something so it's clearer what kind of ID it is.

[bashi, 2016/07/12 05:51:46]

Done.

+
+  // Iterates all children synchronously.
+  using IterateCallback = base::Callback<void(mojom::ChildMemoryCoordinator*)>;
+  void IterateChildrenForTesting(IterateCallback callback);

[dcheng, 2016/07/12 05:20:28]

Nit: pass callbacks by const ref. But rather than having this, I think we should
just friend a test helper that can access the state: it will make the tests very
straightforward, since all the test code will be inline.

[bashi, 2016/07/12 05:51:46]

Hmm, can we make the test helper a friend of this class? The test lives in
content/ but this lives in components/memory_coordinator. Dependency is content/
-> components/memory_coordinator.

+
+ private:
+  void OnConnectionError(int id);
+
+  std::map<int, std::unique_ptr<MemoryCoordinatorHandleImpl>> children_;

[dcheng, 2016/07/12 05:20:28]

And please add a comment here =)

[bashi, 2016/07/12 05:51:46]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(MemoryCoordinator);
+};
+
+}  // memory_coordinator
+
+#endif  // COMPONENTS_MEMORY_COORDINATOR_BROWSER_MEMORY_COORDINATOR_H_