mash: Add SystemTrayClient interface, use to show date settings

chrome/browser/ui/ash/system_tray_client.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 "chrome/browser/ui/ash/system_tray_controller_mus.h"
+#include "chrome/browser/ui/ash/system_tray_client.h"
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_process_platform_part.h"
 #include "chrome/browser/chromeos/system/system_clock.h"
+#include "chrome/browser/ui/ash/system_tray_common.h"
 #include "content/public/common/mojo_shell_connection.h"
 #include "services/shell/public/cpp/connector.h"
 
-SystemTrayControllerMus::SystemTrayControllerMus() {
+SystemTrayClient::SystemTrayClient() : binding_(this) {
+  // Connect to the mojo SystemTray service in ash.
   shell::Connector* connector =
       content::MojoShellConnection::GetForProcess()->GetConnector();
   connector->ConnectToInterface("mojo:ash", &system_tray_);
 
+  // Register this object as the SystemTrayClient interface implementation.
+  system_tray_->SetClient(binding_.CreateInterfacePtrAndBind());
+
   g_browser_process->platform_part()->GetSystemClock()->AddObserver(this);
 }
 
-SystemTrayControllerMus::~SystemTrayControllerMus() {
+SystemTrayClient::~SystemTrayClient() {
   g_browser_process->platform_part()->GetSystemClock()->RemoveObserver(this);
 }
 
-void SystemTrayControllerMus::OnSystemClockChanged(
+void SystemTrayClient::ShowDateSettings() {
+  SystemTrayCommon::ShowDateSettings();
+}
+
+void SystemTrayClient::OnSystemClockChanged(
     chromeos::system::SystemClock* clock) {
   system_tray_->SetUse24HourClock(clock->ShouldUse24HourClock());
 }