Use mojo SystemTray interfaces for both mash and classic ash

ash/common/system/tray/system_tray_controller.h

Index: ash/common/system/tray/system_tray_controller.h
diff --git a/ash/common/system/tray/system_tray_controller.h b/ash/common/system/tray/system_tray_controller.h
new file mode 100644
index 0000000000000000000000000000000000000000..3bb09d3d90a5cd080cd43c84d2db255c79661e47
--- /dev/null
+++ b/ash/common/system/tray/system_tray_controller.h
@@ -0,0 +1,73 @@
+// 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 ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_CONTROLLER_H_
+#define ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_CONTROLLER_H_
+
+#include "ash/public/interfaces/system_tray.mojom.h"
+#include "base/i18n/time_formatting.h"
+#include "base/macros.h"
+#include "base/observer_list.h"

[msw, 2016/09/30 23:26:49]

nit: remove

[James Cook, 2016/10/03 18:07:56]

Done.

+#include "mojo/public/cpp/bindings/binding_set.h"
+
+namespace shell {
+class Connector;
+}
+
+namespace ash {
+
+class ClockObserver;

[msw, 2016/09/30 23:26:49]

nit: remove

[James Cook, 2016/10/03 18:07:56]

Done.

+
+// Wrapper around the mojom::SystemTrayClient interface that makes the initial

[msw, 2016/09/30 23:26:48]

nit: mention that it implements mojom::SystemTray?

[James Cook, 2016/10/03 18:07:55]

Rewrote.

+// connection and reconnects on error. Also caches state pushed down from chrome
+// browser to allow synchronous access to the state. Conceptually similar to
+// historical ash-to-chrome interfaces like SystemTrayDelegate. Lives on the
+// main thread.
+//
+// Only connects to the actual mojom::SystemTrayClient interface when running on
+// Chrome OS. In tests and on Windows all operations are no-ops.
+//
+// TODO: Consider renaming this to SystemTrayClient or renaming the current

[msw, 2016/09/30 23:26:49]

I definitely favor the latter option :)

+// SystemTray to SystemTrayView and making this class SystemTray.
+class SystemTrayController : public mojom::SystemTray {
+ public:
+  explicit SystemTrayController(shell::Connector* connector);
+  ~SystemTrayController() override;
+
+  // Wrappers around the mojom::SystemTrayClient interface.
+  base::HourClockType GetHourClockType() const;
+  void ShowDateSettings();
+

[James Cook, 2016/09/30 21:18:27]

The other ShowFoo() methods will end up here.

[msw, 2016/09/30 23:26:49]

Acknowledged.

+  // Binds the mojom::SystemTray interface to this object.
+  void BindRequest(mojom::SystemTrayRequest request);
+
+ private:
+  // Connects or reconnects to the mojom::SystemTrayClient interface when
+  // running on Chrome OS. Otherwise does nothing.
+  void ConnectToSystemTrayClient();
+
+  // Handles errors on the |system_tray_client_| interface connection.
+  void OnClientConnectionError();
+
+  // mojom::SystemTray:
+  void SetUse24HourClock(bool use_24_hour) override;
+
+  // May be null in unit tests.
+  shell::Connector* connector_;
+
+  // Client interface in chrome browser. Only bound on Chrome OS.
+  mojom::SystemTrayClientPtr system_tray_client_;
+
+  // Bindings for the SystemTray interface.
+  mojo::BindingSet<mojom::SystemTray> bindings_;
+
+  // 12 or 24 hour display.

[msw, 2016/09/30 23:26:49]

optional nit: The type of hour display: 12 or 24 hours.

[James Cook, 2016/10/03 18:07:56]

Done.

+  base::HourClockType hour_clock_type_;
+
+  DISALLOW_COPY_AND_ASSIGN(SystemTrayController);
+};
+
+}  // namspace ash
+
+#endif  // ASH_COMMON_SYSTEM_TRAY_SYSTEM_TRAY_CONTROLLER_H_