chromeos: Refactor system tray "show settings" commands to use mojo

ash/common/system/tray/system_tray_delegate.cc

Index: ash/common/system/tray/system_tray_delegate.cc
diff --git a/ash/common/system/tray/system_tray_delegate.cc b/ash/common/system/tray/system_tray_delegate.cc
index 346884b182c0a957d027c0ca0db404d46d06826a..bc6e86eb228100c0ca91cf930741a8d268146e55 100644
--- a/ash/common/system/tray/system_tray_delegate.cc
+++ b/ash/common/system/tray/system_tray_delegate.cc
@@ -77,8 +77,6 @@ void SystemTrayDelegate::GetSystemUpdateInfo(UpdateInfo* info) const {
   info->factory_reset_required = false;
 }
 
-void SystemTrayDelegate::ShowSettings() {}
-
 bool SystemTrayDelegate::ShouldShowSettings() {
   return false;
 }
@@ -87,30 +85,10 @@ void SystemTrayDelegate::ShowSetTimeDialog() {}
 
 void SystemTrayDelegate::ShowNetworkSettingsForGuid(const std::string& guid) {}
 
-void SystemTrayDelegate::ShowDisplaySettings() {}
-
-void SystemTrayDelegate::ShowPowerSettings() {}
-
-void SystemTrayDelegate::ShowChromeSlow() {}
-
 bool SystemTrayDelegate::ShouldShowDisplayNotification() {
   return false;
 }
 
-void SystemTrayDelegate::ShowIMESettings() {}
-
-void SystemTrayDelegate::ShowHelp() {}
-
-void SystemTrayDelegate::ShowAccessibilityHelp() {}
-
-void SystemTrayDelegate::ShowAccessibilitySettings() {}
-
-void SystemTrayDelegate::ShowPaletteHelp() {}
-
-void SystemTrayDelegate::ShowPaletteSettings() {}
-
-void SystemTrayDelegate::ShowPublicAccountInfo() {}
-
 void SystemTrayDelegate::ShowEnterpriseInfo() {}
 
 void SystemTrayDelegate::ShowUserLogin() {}
@@ -162,8 +140,6 @@ bool SystemTrayDelegate::GetBluetoothDiscovering() {
   return false;
 }
 
-void SystemTrayDelegate::ShowProxySettings() {}
-
 CastConfigDelegate* SystemTrayDelegate::GetCastConfigDelegate() {
   return nullptr;
 }