Remove empty DiskMountManager::Observer overrides

crrev.com/1ffee348 changed these methods to
no longer be pure-virtual. This change is intended to make the code more
consistent (and delete a bunch of useless code).

BUG=None

Change-Id: I27c5ee5b58e94deeed380603e10f54ea316f30ef
Reviewed-on: https://chromium-review.googlesource.com/1152345Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Yusuke Sato <yusukes@chromium.org>
Commit-Queue: Anand Mistry <amistry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#579245}

chrome/browser/chromeos/app_mode/kiosk_external_updater.cc

@@ -105,19 +105,6 @@ KioskExternalUpdater::~KioskExternalUpdater() {
     disks::DiskMountManager::GetInstance()->RemoveObserver(this);
 }
 
-void KioskExternalUpdater::OnAutoMountableDiskEvent(
-    disks::DiskMountManager::DiskEvent event,
-    const disks::DiskMountManager::Disk& disk) {}
-
-void KioskExternalUpdater::OnBootDeviceDiskEvent(
-    disks::DiskMountManager::DiskEvent event,
-    const disks::DiskMountManager::Disk& disk) {}
-
-void KioskExternalUpdater::OnDeviceEvent(
-    disks::DiskMountManager::DeviceEvent event,
-    const std::string& device_path) {
-}
-
 void KioskExternalUpdater::OnMountEvent(
     disks::DiskMountManager::MountEvent event,
     MountError error_code,

chrome/browser/chromeos/app_mode/kiosk_external_updater.h

@@ -57,14 +57,6 @@ class KioskExternalUpdater : public disks::DiskMountManager::Observer,
   };
 
   // disks::DiskMountManager::Observer overrides.
-  void OnAutoMountableDiskEvent(
-      disks::DiskMountManager::DiskEvent event,
-      const disks::DiskMountManager::Disk& disk) override;
-  void OnBootDeviceDiskEvent(
-      disks::DiskMountManager::DiskEvent event,
-      const disks::DiskMountManager::Disk& disk) override;
-  void OnDeviceEvent(disks::DiskMountManager::DeviceEvent event,
-                     const std::string& device_path) override;
   void OnMountEvent(
       disks::DiskMountManager::MountEvent event,
       MountError error_code,

chrome/browser/chromeos/file_manager/volume_manager.cc

@@ -688,10 +688,6 @@ void VolumeManager::OnAutoMountableDiskEvent(
   NOTREACHED();
 }
 
-void VolumeManager::OnBootDeviceDiskEvent(
-    chromeos::disks::DiskMountManager::DiskEvent event,
-    const chromeos::disks::DiskMountManager::Disk& disk) {}
-
 void VolumeManager::OnDeviceEvent(
     chromeos::disks::DiskMountManager::DeviceEvent event,
     const std::string& device_path) {

chrome/browser/chromeos/file_manager/volume_manager.h

@@ -317,9 +317,6 @@ class VolumeManager : public KeyedService,
   void OnAutoMountableDiskEvent(
       chromeos::disks::DiskMountManager::DiskEvent event,
       const chromeos::disks::DiskMountManager::Disk& disk) override;
-  void OnBootDeviceDiskEvent(
-      chromeos::disks::DiskMountManager::DiskEvent event,
-      const chromeos::disks::DiskMountManager::Disk& disk) override;
   void OnDeviceEvent(chromeos::disks::DiskMountManager::DeviceEvent event,
                      const std::string& device_path) override;
   void OnMountEvent(chromeos::disks::DiskMountManager::MountEvent event,

components/arc/volume_mounter/arc_volume_mounter_bridge.cc

@@ -77,38 +77,6 @@ void ArcVolumeMounterBridge::OnConnectionReady() {
                                 weak_ptr_factory_.GetWeakPtr()));
 }
 
-void ArcVolumeMounterBridge::OnAutoMountableDiskEvent(
-    chromeos::disks::DiskMountManager::DiskEvent event,
-    const chromeos::disks::DiskMountManager::Disk& disk) {
-  // Ignored. DiskEvents will be maintained in Vold during MountEvents.
-}
-
-void ArcVolumeMounterBridge::OnBootDeviceDiskEvent(
-    chromeos::disks::DiskMountManager::DiskEvent event,
-    const chromeos::disks::DiskMountManager::Disk& disk) {
-  // Ignored. ARC doesn't care about boot device disk events.
-}
-
-void ArcVolumeMounterBridge::OnDeviceEvent(
-    chromeos::disks::DiskMountManager::DeviceEvent event,
-    const std::string& device_path) {
-  // Ignored. ARC doesn't care about events other than Disk and Mount events.
-}
-
-void ArcVolumeMounterBridge::OnFormatEvent(
-    chromeos::disks::DiskMountManager::FormatEvent event,
-    chromeos::FormatError error_code,
-    const std::string& device_path) {
-  // Ignored. ARC doesn't care about events other than Disk and Mount events.
-}
-
-void ArcVolumeMounterBridge::OnRenameEvent(
-    chromeos::disks::DiskMountManager::RenameEvent event,
-    chromeos::RenameError error_code,
-    const std::string& device_path) {
-  // Ignored. ARC doesn't care about events other than Disk and Mount events.
-}
-
 void ArcVolumeMounterBridge::OnMountEvent(
     DiskMountManager::MountEvent event,
     chromeos::MountError error_code,

components/arc/volume_mounter/arc_volume_mounter_bridge.h

@@ -44,24 +44,10 @@ class ArcVolumeMounterBridge
   void OnConnectionReady() override;
 
   // chromeos::disks::DiskMountManager::Observer overrides:
-  void OnAutoMountableDiskEvent(
-      chromeos::disks::DiskMountManager::DiskEvent event,
-      const chromeos::disks::DiskMountManager::Disk& disk) override;
-  void OnBootDeviceDiskEvent(
-      chromeos::disks::DiskMountManager::DiskEvent event,
-      const chromeos::disks::DiskMountManager::Disk& disk) override;
-  void OnDeviceEvent(chromeos::disks::DiskMountManager::DeviceEvent event,
-                     const std::string& device_path) override;
   void OnMountEvent(chromeos::disks::DiskMountManager::MountEvent event,
                     chromeos::MountError error_code,
                     const chromeos::disks::DiskMountManager::MountPointInfo&
                         mount_info) override;
-  void OnFormatEvent(chromeos::disks::DiskMountManager::FormatEvent event,
-                     chromeos::FormatError error_code,
-                     const std::string& device_path) override;
-  void OnRenameEvent(chromeos::disks::DiskMountManager::RenameEvent event,
-                     chromeos::RenameError error_code,
-                     const std::string& device_path) override;
 
   // mojom::VolumeMounterHost overrides:
   void RequestAllMountPoints() override;

components/storage_monitor/storage_monitor_chromeos.cc

@@ -162,10 +162,6 @@ void StorageMonitorCros::CheckExistingMountPoints() {
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
-void StorageMonitorCros::OnAutoMountableDiskEvent(
-    DiskMountManager::DiskEvent event,
-    const DiskMountManager::Disk& disk) {}
-
 void StorageMonitorCros::OnBootDeviceDiskEvent(
     DiskMountManager::DiskEvent event,
     const DiskMountManager::Disk& disk) {
@@ -191,9 +187,6 @@ void StorageMonitorCros::OnBootDeviceDiskEvent(
   }
 }
 
-void StorageMonitorCros::OnDeviceEvent(DiskMountManager::DeviceEvent event,
-                                       const std::string& device_path) {}
-
 void StorageMonitorCros::OnMountEvent(
     DiskMountManager::MountEvent event,
     chromeos::MountError error_code,
@@ -235,14 +228,6 @@ void StorageMonitorCros::OnMountEvent(
   }
 }
 
-void StorageMonitorCros::OnFormatEvent(DiskMountManager::FormatEvent event,
-                                       chromeos::FormatError error_code,
-                                       const std::string& device_path) {}
-
-void StorageMonitorCros::OnRenameEvent(DiskMountManager::RenameEvent event,
-                                       chromeos::RenameError error_code,
-                                       const std::string& device_path) {}
-
 void StorageMonitorCros::SetMediaTransferProtocolManagerForTest(
     device::mojom::MtpManagerPtr test_manager) {
   DCHECK(!mtp_device_manager_);

components/storage_monitor/storage_monitor_chromeos.h

@@ -46,24 +46,13 @@ class StorageMonitorCros : public StorageMonitor,
       device::mojom::MtpManagerPtr test_manager);
 
   // chromeos::disks::DiskMountManager::Observer implementation.
-  void OnAutoMountableDiskEvent(
-      chromeos::disks::DiskMountManager::DiskEvent event,
-      const chromeos::disks::DiskMountManager::Disk& disk) override;
   void OnBootDeviceDiskEvent(
       chromeos::disks::DiskMountManager::DiskEvent event,
       const chromeos::disks::DiskMountManager::Disk& disk) override;
-  void OnDeviceEvent(chromeos::disks::DiskMountManager::DeviceEvent event,
-                     const std::string& device_path) override;
   void OnMountEvent(chromeos::disks::DiskMountManager::MountEvent event,
                     chromeos::MountError error_code,
                     const chromeos::disks::DiskMountManager::MountPointInfo&
                         mount_info) override;
-  void OnFormatEvent(chromeos::disks::DiskMountManager::FormatEvent event,
-                     chromeos::FormatError error_code,
-                     const std::string& device_path) override;
-  void OnRenameEvent(chromeos::disks::DiskMountManager::RenameEvent event,
-                     chromeos::RenameError error_code,
-                     const std::string& device_path) override;
 
   // StorageMonitor implementation.
   bool GetStorageInfoForPath(const base::FilePath& path,