Remove the drive status from the ash try.

ash/system/tray/default_system_tray_delegate.cc

Index: ash/system/tray/default_system_tray_delegate.cc
diff --git a/ash/system/tray/default_system_tray_delegate.cc b/ash/system/tray/default_system_tray_delegate.cc
index 839575beff2e7b5f7405c483a08286d4001fa0b1..e2aeae30744d6dca3f4081bac4f5ed37a55f72e6 100644
--- a/ash/system/tray/default_system_tray_delegate.cc
+++ b/ash/system/tray/default_system_tray_delegate.cc
@@ -124,9 +124,6 @@ bool DefaultSystemTrayDelegate::ShouldShowDisplayNotification() {
   return false;
 }
 
-void DefaultSystemTrayDelegate::ShowDriveSettings() {
-}
-
 void DefaultSystemTrayDelegate::ShowIMESettings() {
 }
 
@@ -205,13 +202,6 @@ void DefaultSystemTrayDelegate::SwitchIME(const std::string& ime_id) {
 void DefaultSystemTrayDelegate::ActivateIMEProperty(const std::string& key) {
 }
 
-void DefaultSystemTrayDelegate::CancelDriveOperation(int32 operation_id) {
-}
-
-void DefaultSystemTrayDelegate::GetDriveOperationStatusList(
-    ash::DriveOperationStatusList*) {
-}
-
 void DefaultSystemTrayDelegate::ShowNetworkConfigure(
     const std::string& network_id,
     gfx::NativeWindow parent_window) {