Convert Pass()→std::move() in //chrome/browser/ui

chrome/browser/sync_file_system/drive_backend/remote_to_local_syncer.cc

 // Copyright 2013 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/sync_file_system/drive_backend/remote_to_local_syncer.h"
 
 #include <stdint.h>
-
 #include <limits>
+#include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/files/file_util.h"
 #include "base/format_macros.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "base/task_runner_util.h"
 #include "chrome/browser/sync_file_system/drive_backend/callback_helper.h"
@@ skipping 50 matching lines @@
     return app_root_tracker.tracker_kind() == TRACKER_KIND_DISABLED_APP_ROOT;
   }
   return false;
 }
 
 scoped_ptr<FileMetadata> GetFileMetadata(MetadataDatabase* database,
                                          const std::string& file_id) {
   scoped_ptr<FileMetadata> metadata(new FileMetadata);
   if (!database->FindFileByFileID(file_id, metadata.get()))
     metadata.reset();
-  return metadata.Pass();
+  return metadata;
 }
 
 // Creates a temporary file in |dir_path|.  This must be called on an
 // IO-allowed task runner, and the runner must be given as |file_task_runner|.
 storage::ScopedFile CreateTemporaryFile(
     const scoped_refptr<base::TaskRunner>& file_task_runner) {
   base::FilePath temp_file_path;
   if (!base::CreateTemporaryFile(&temp_file_path))
     return storage::ScopedFile();
 
@@ skipping 14 matching lines @@
 }
 
 RemoteToLocalSyncer::~RemoteToLocalSyncer() {
 }
 
 void RemoteToLocalSyncer::RunPreflight(scoped_ptr<SyncTaskToken> token) {
   token->InitializeTaskLog("Remote -> Local");
 
   if (!drive_service() || !metadata_database() || !remote_change_processor()) {
     token->RecordLog("Context not ready.");
-    SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_FAILED);
+    SyncTaskManager::NotifyTaskDone(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
 
   dirty_tracker_ = make_scoped_ptr(new FileTracker);
   if (metadata_database()->GetDirtyTracker(dirty_tracker_.get())) {
     token->RecordLog(base::StringPrintf(
         "Start: tracker_id=%" PRId64, dirty_tracker_->tracker_id()));
     metadata_database()->DemoteTracker(dirty_tracker_->tracker_id());
-    ResolveRemoteChange(token.Pass());
+    ResolveRemoteChange(std::move(token));
     return;
   }
 
   token->RecordLog("Nothing to do.");
-  SyncTaskManager::NotifyTaskDone(token.Pass(), SYNC_STATUS_NO_CHANGE_TO_SYNC);
+  SyncTaskManager::NotifyTaskDone(std::move(token),
+                                  SYNC_STATUS_NO_CHANGE_TO_SYNC);
 }
 
 void RemoteToLocalSyncer::ResolveRemoteChange(scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
   remote_metadata_ = GetFileMetadata(
       metadata_database(), dirty_tracker_->file_id());
 
   if (!remote_metadata_ || !remote_metadata_->has_details()) {
     if (remote_metadata_ && !remote_metadata_->has_details()) {
       token->RecordLog(
           "Missing details of a remote file: " + remote_metadata_->file_id());
       NOTREACHED();
     }
     token->RecordLog("Missing remote metadata case.");
 
     MoveToBackground(
-        token.Pass(),
+        std::move(token),
         base::Bind(&RemoteToLocalSyncer::HandleMissingRemoteMetadata,
                    weak_ptr_factory_.GetWeakPtr()));
     return;
   }
 
   DCHECK(remote_metadata_);
   DCHECK(remote_metadata_->has_details());
   const FileDetails& remote_details = remote_metadata_->details();
 
   if (!dirty_tracker_->active() ||
       HasDisabledAppRoot(metadata_database(), *dirty_tracker_)) {
     // Handle inactive tracker in SyncCompleted.
     token->RecordLog("Inactive tracker case.");
-    SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+    SyncCompleted(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   DCHECK(dirty_tracker_->active());
   DCHECK(!HasDisabledAppRoot(metadata_database(), *dirty_tracker_));
 
   if (!dirty_tracker_->has_synced_details()) {
     token->RecordLog(base::StringPrintf(
         "Missing synced_details of an active tracker: %" PRId64,
         dirty_tracker_->tracker_id()));
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
 
   DCHECK(dirty_tracker_->has_synced_details());
   const FileDetails& synced_details = dirty_tracker_->synced_details();
 
   if (dirty_tracker_->tracker_id() ==
       metadata_database()->GetSyncRootTrackerID()) {
     if (remote_details.missing() ||
         synced_details.title() != remote_details.title() ||
         remote_details.parent_folder_ids_size()) {
       token->RecordLog("Sync-root deletion.");
       sync_root_deletion_ = true;
-      SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+      SyncCompleted(std::move(token), SYNC_STATUS_OK);
       return;
     }
     token->RecordLog("Trivial sync-root change.");
-    SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+    SyncCompleted(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   DCHECK_NE(dirty_tracker_->tracker_id(),
             metadata_database()->GetSyncRootTrackerID());
 
   if (!BuildFileSystemURL(metadata_database(), *dirty_tracker_, &url_)) {
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
 
   DCHECK(url_.is_valid());
 
   if (remote_details.missing()) {
     if (!synced_details.missing()) {
       token->RecordLog("Remote file deletion.");
-      MoveToBackground(token.Pass(),
+      MoveToBackground(std::move(token),
                        base::Bind(&RemoteToLocalSyncer::HandleDeletion,
                                   weak_ptr_factory_.GetWeakPtr()));
       return;
     }
 
     DCHECK(synced_details.missing());
     token->RecordLog("Found a stray missing tracker: " +
                      dirty_tracker_->file_id());
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+    SyncCompleted(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   // Most of remote_details field is valid from here.
   DCHECK(!remote_details.missing());
 
   if (synced_details.file_kind() != remote_details.file_kind()) {
     token->RecordLog(base::StringPrintf(
         "Found type mismatch between remote and local file: %s"
         " type: (local) %d vs (remote) %d",
         dirty_tracker_->file_id().c_str(),
         synced_details.file_kind(),
         remote_details.file_kind()));
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
   DCHECK_EQ(synced_details.file_kind(), remote_details.file_kind());
 
   if (synced_details.file_kind() == FILE_KIND_UNSUPPORTED) {
     token->RecordLog("Found an unsupported active file: " +
                      remote_metadata_->file_id());
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
   DCHECK(remote_details.file_kind() == FILE_KIND_FILE ||
          remote_details.file_kind() == FILE_KIND_FOLDER);
 
   if (synced_details.title() != remote_details.title()) {
     // Handle rename as deletion + addition.
     token->RecordLog("Detected file rename.");
 
-    MoveToBackground(token.Pass(),
+    MoveToBackground(std::move(token),
                      base::Bind(&RemoteToLocalSyncer::HandleFileMove,
                                 weak_ptr_factory_.GetWeakPtr()));
     return;
   }
   DCHECK_EQ(synced_details.title(), remote_details.title());
 
   FileTracker parent_tracker;
   if (!metadata_database()->FindTrackerByTrackerID(
           dirty_tracker_->parent_tracker_id(), &parent_tracker)) {
     token->RecordLog("Missing parent tracker for a non sync-root tracker: "
                      + dirty_tracker_->file_id());
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
 
   if (!HasFolderAsParent(remote_details, parent_tracker.file_id())) {
     // Handle reorganize as deletion + addition.
     token->RecordLog("Detected file reorganize.");
 
-    MoveToBackground(token.Pass(),
+    MoveToBackground(std::move(token),
                      base::Bind(&RemoteToLocalSyncer::HandleFileMove,
                                 weak_ptr_factory_.GetWeakPtr()));
     return;
   }
 
   if (synced_details.file_kind() == FILE_KIND_FILE) {
     if (synced_details.md5() != remote_details.md5()) {
       token->RecordLog("Detected file content update.");
-      MoveToBackground(token.Pass(),
+      MoveToBackground(std::move(token),
                        base::Bind(&RemoteToLocalSyncer::HandleContentUpdate,
                                   weak_ptr_factory_.GetWeakPtr()));
       return;
     }
   } else {
     DCHECK_EQ(FILE_KIND_FOLDER, synced_details.file_kind());
     if (synced_details.missing()) {
       token->RecordLog("Detected folder update.");
-      MoveToBackground(token.Pass(),
+      MoveToBackground(std::move(token),
                        base::Bind(&RemoteToLocalSyncer::HandleFolderUpdate,
                                   weak_ptr_factory_.GetWeakPtr()));
       return;
     }
     if (dirty_tracker_->needs_folder_listing()) {
       token->RecordLog("Needs listing folder.");
-      MoveToBackground(token.Pass(),
+      MoveToBackground(std::move(token),
                        base::Bind(&RemoteToLocalSyncer::ListFolderContent,
                                   weak_ptr_factory_.GetWeakPtr()));
       return;
     }
-    SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+    SyncCompleted(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   token->RecordLog("Trivial file change.");
-  SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+  SyncCompleted(std::move(token), SYNC_STATUS_OK);
 }
 
 void RemoteToLocalSyncer::MoveToBackground(scoped_ptr<SyncTaskToken> token,
                                            const Continuation& continuation) {
   DCHECK(dirty_tracker_);
 
   scoped_ptr<TaskBlocker> blocker(new TaskBlocker);
   blocker->app_id = dirty_tracker_->app_id();
   if (url_.is_valid())
     blocker->paths.push_back(url_.path());
   blocker->file_ids.push_back(dirty_tracker_->file_id());
   blocker->tracker_ids.push_back(dirty_tracker_->tracker_id());
 
   SyncTaskManager::UpdateTaskBlocker(
-      token.Pass(), blocker.Pass(),
+      std::move(token), std::move(blocker),
       base::Bind(&RemoteToLocalSyncer::ContinueAsBackgroundTask,
                  weak_ptr_factory_.GetWeakPtr(), continuation));
 }
 
 void RemoteToLocalSyncer::ContinueAsBackgroundTask(
     const Continuation& continuation,
     scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
 
   // The SyncTask runs as a background task beyond this point.
@@ skipping 12 matching lines @@
   // - For other RemoteToLocalSyncer, it may delete the FileTracker of parent.
   //   Note that since RemoteToLocalSyncer demotes the target FileTracker first,
   //   any other RemoteToLocalSyncer does not run for current |dirty_tracker_|.
   // - Others, SyncEngineInitializer and RegisterAppTask doesn't affect to
 
   FileTracker latest_dirty_tracker;
   if (!metadata_database()->FindTrackerByTrackerID(
           dirty_tracker_->tracker_id(), &latest_dirty_tracker) ||
       dirty_tracker_->active() != latest_dirty_tracker.active() ||
       !latest_dirty_tracker.dirty()) {
-    SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+    SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
     return;
   }
 
   int64_t current_change_id = std::numeric_limits<int64_t>::min();
   int64_t latest_change_id = std::numeric_limits<int64_t>::min();
   if (dirty_tracker_->has_synced_details())
     current_change_id = dirty_tracker_->synced_details().change_id();
   if (latest_dirty_tracker.has_synced_details())
     latest_change_id = latest_dirty_tracker.synced_details().change_id();
   if (current_change_id != latest_change_id) {
-    SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+    SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
     return;
   }
 
   FileMetadata latest_file_metadata;
   if (metadata_database()->FindFileByFileID(dirty_tracker_->file_id(),
                                             &latest_file_metadata)) {
     if (!remote_metadata_) {
-      SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+      SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
       return;
     }
 
     int64_t change_id = remote_metadata_->details().change_id();
     int64_t latest_change_id = latest_file_metadata.details().change_id();
     if (change_id != latest_change_id) {
-      SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+      SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
       return;
     }
   } else {
     if (remote_metadata_) {
-      SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+      SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
       return;
     }
   }
-  continuation.Run(token.Pass());
+  continuation.Run(std::move(token));
 }
 
 void RemoteToLocalSyncer::HandleMissingRemoteMetadata(
     scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
 
   drive_service()->GetFileResource(
       dirty_tracker_->file_id(),
       base::Bind(&RemoteToLocalSyncer::DidGetRemoteMetadata,
                  weak_ptr_factory_.GetWeakPtr(),
                  base::Passed(&token)));
 }
 
 void RemoteToLocalSyncer::DidGetRemoteMetadata(
     scoped_ptr<SyncTaskToken> token,
     google_apis::DriveApiErrorCode error,
     scoped_ptr<google_apis::FileResource> entry) {
   DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 
   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
   if (status != SYNC_STATUS_OK &&
       error != google_apis::HTTP_NOT_FOUND) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   if (error == google_apis::HTTP_NOT_FOUND) {
     status = metadata_database()->UpdateByDeletedRemoteFile(
         dirty_tracker_->file_id());
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   if (!entry) {
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
 
   status = metadata_database()->UpdateByFileResource(*entry);
   if (status != SYNC_STATUS_OK) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   metadata_database()->PromoteDemotedTracker(dirty_tracker_->tracker_id());
 
   // Do not update |dirty_tracker_|.
-  SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+  SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
 }
 
 void RemoteToLocalSyncer::DidPrepareForAddOrUpdateFile(
     scoped_ptr<SyncTaskToken> token,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   DCHECK(url_.is_valid());
   DCHECK(local_metadata_);
   DCHECK(local_changes_);
 
   // Check if the local file exists.
   if (local_metadata_->file_type == SYNC_FILE_TYPE_UNKNOWN ||
       (!local_changes_->empty() && local_changes_->back().IsDelete())) {
     file_type_ = SYNC_FILE_TYPE_FILE;
     sync_action_ = SYNC_ACTION_ADDED;
     // Missing local file case.
     // Download the file and add it to local as a new file.
-    DownloadFile(token.Pass());
+    DownloadFile(std::move(token));
     return;
   }
 
   DCHECK(local_changes_->empty() || local_changes_->back().IsAddOrUpdate());
   if (local_changes_->empty()) {
     if (local_metadata_->file_type == SYNC_FILE_TYPE_FILE) {
       file_type_ = SYNC_FILE_TYPE_FILE;
       sync_action_ = SYNC_ACTION_UPDATED;
       // Download the file and overwrite the existing local file.
-      DownloadFile(token.Pass());
+      DownloadFile(std::move(token));
       return;
     }
 
     DCHECK_EQ(SYNC_FILE_TYPE_DIRECTORY, local_metadata_->file_type);
 
     // Got a remote regular file modification for existing local folder.
     // Our policy prioritize folders in this case.
     // Let local-to-remote sync phase process this change.
     remote_change_processor()->RecordFakeLocalChange(
-        url_,
-        FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE,
-                   local_metadata_->file_type),
-        SyncCompletedCallback(token.Pass()));
+        url_, FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE,
+                         local_metadata_->file_type),
+        SyncCompletedCallback(std::move(token)));
     return;
   }
 
   DCHECK(local_changes_->back().IsAddOrUpdate());
   // Conflict case.
   // Do nothing for the change now, and handle this in LocalToRemoteSync phase.
-  SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+  SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
 }
 
 void RemoteToLocalSyncer::HandleFolderUpdate(
     scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
   DCHECK(dirty_tracker_->active());
   DCHECK(!HasDisabledAppRoot(metadata_database(), *dirty_tracker_));
 
   DCHECK(remote_metadata_);
   DCHECK(remote_metadata_->has_details());
   DCHECK(!remote_metadata_->details().missing());
   DCHECK_EQ(FILE_KIND_FOLDER, remote_metadata_->details().file_kind());
 
   Prepare(base::Bind(&RemoteToLocalSyncer::DidPrepareForFolderUpdate,
                      weak_ptr_factory_.GetWeakPtr(),
                      base::Passed(&token)));
 }
 
 void RemoteToLocalSyncer::DidPrepareForFolderUpdate(
     scoped_ptr<SyncTaskToken> token,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   DCHECK(url_.is_valid());
   DCHECK(local_metadata_);
   DCHECK(local_changes_);
 
   // Check if the local file exists.
   if (local_metadata_->file_type == SYNC_FILE_TYPE_UNKNOWN ||
       (!local_changes_->empty() && local_changes_->back().IsDelete())) {
     file_type_ = SYNC_FILE_TYPE_DIRECTORY;
     sync_action_ = SYNC_ACTION_ADDED;
     // No local file exists at the path.
-    CreateFolder(token.Pass());
+    CreateFolder(std::move(token));
     return;
   }
 
   if (local_metadata_->file_type == SYNC_FILE_TYPE_DIRECTORY) {
     // There already exists a folder, nothing left to do.
     if (dirty_tracker_->needs_folder_listing() &&
         !dirty_tracker_->synced_details().missing()) {
-      ListFolderContent(token.Pass());
+      ListFolderContent(std::move(token));
     } else {
-      SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+      SyncCompleted(std::move(token), SYNC_STATUS_OK);
     }
     return;
   }
 
   DCHECK_EQ(SYNC_FILE_TYPE_FILE, local_metadata_->file_type);
   file_type_ = SYNC_FILE_TYPE_DIRECTORY;
   sync_action_ = SYNC_ACTION_ADDED;
   // Got a remote folder for existing local file.
   // Our policy prioritize folders in this case.
-  CreateFolder(token.Pass());
+  CreateFolder(std::move(token));
 }
 
 void RemoteToLocalSyncer::HandleDeletion(
     scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
   DCHECK(dirty_tracker_->active());
   DCHECK(!HasDisabledAppRoot(metadata_database(), *dirty_tracker_));
   DCHECK(dirty_tracker_->has_synced_details());
   DCHECK(!dirty_tracker_->synced_details().missing());
 
@@ skipping 18 matching lines @@
 
   Prepare(base::Bind(&RemoteToLocalSyncer::DidPrepareForDeletion,
                      weak_ptr_factory_.GetWeakPtr(),
                      base::Passed(&token)));
 }
 
 void RemoteToLocalSyncer::DidPrepareForDeletion(
     scoped_ptr<SyncTaskToken> token,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   DCHECK(url_.is_valid());
   DCHECK(local_metadata_);
   DCHECK(local_changes_);
 
   // Check if the local file exists.
   if (local_metadata_->file_type == SYNC_FILE_TYPE_UNKNOWN ||
       (!local_changes_->empty() && local_changes_->back().IsDelete())) {
     // No local file exists at the path.
-    SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+    SyncCompleted(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   DCHECK(local_changes_->empty() || local_changes_->back().IsAddOrUpdate());
   if (local_changes_->empty()) {
     file_type_ = local_metadata_->file_type;
     sync_action_ = SYNC_ACTION_DELETED;
-    DeleteLocalFile(token.Pass());
+    DeleteLocalFile(std::move(token));
     return;
   }
 
   DCHECK(local_changes_->back().IsAddOrUpdate());
   // File is remotely deleted and locally updated.
   // Ignore the remote deletion and handle it as if applied successfully.
-  SyncCompleted(token.Pass(), SYNC_STATUS_OK);
+  SyncCompleted(std::move(token), SYNC_STATUS_OK);
 }
 
 void RemoteToLocalSyncer::HandleContentUpdate(
     scoped_ptr<SyncTaskToken> token) {
   DCHECK(dirty_tracker_);
   DCHECK(dirty_tracker_->active());
   DCHECK(!HasDisabledAppRoot(metadata_database(), *dirty_tracker_));
   DCHECK(dirty_tracker_->has_synced_details());
   DCHECK_EQ(FILE_KIND_FILE, dirty_tracker_->synced_details().file_kind());
 
@@ skipping 31 matching lines @@
                  base::Passed(make_scoped_ptr(new FileIDList))));
 }
 
 void RemoteToLocalSyncer::DidListFolderContent(
     scoped_ptr<SyncTaskToken> token,
     scoped_ptr<FileIDList> children,
     google_apis::DriveApiErrorCode error,
     scoped_ptr<google_apis::FileList> file_list) {
   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
   if (status != SYNC_STATUS_OK) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   if (!file_list) {
     NOTREACHED();
-    SyncCompleted(token.Pass(), SYNC_STATUS_FAILED);
+    SyncCompleted(std::move(token), SYNC_STATUS_FAILED);
     return;
   }
 
   children->reserve(children->size() + file_list->items().size());
   for (ScopedVector<google_apis::FileResource>::const_iterator itr =
            file_list->items().begin();
        itr != file_list->items().end();
        ++itr) {
     children->push_back((*itr)->file_id());
   }
 
   if (!file_list->next_link().is_empty()) {
     drive_service()->GetRemainingFileList(
         file_list->next_link(),
         base::Bind(&RemoteToLocalSyncer::DidListFolderContent,
                    weak_ptr_factory_.GetWeakPtr(),
                    base::Passed(&token), base::Passed(&children)));
     return;
   }
 
   status = metadata_database()->PopulateFolderByChildList(
       dirty_tracker_->file_id(), *children);
-  SyncCompleted(token.Pass(), status);
+  SyncCompleted(std::move(token), status);
 }
 
 void RemoteToLocalSyncer::SyncCompleted(scoped_ptr<SyncTaskToken> token,
                                         SyncStatusCode status) {
   token->RecordLog(base::StringPrintf(
       "[Remote -> Local]: Finished: action=%s, tracker=%" PRId64 " status=%s",
       SyncActionToString(sync_action_), dirty_tracker_->tracker_id(),
       SyncStatusCodeToString(status)));
 
   if (sync_root_deletion_) {
-    FinalizeSync(token.Pass(), SYNC_STATUS_OK);
+    FinalizeSync(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   if (status == SYNC_STATUS_RETRY) {
-    FinalizeSync(token.Pass(), SYNC_STATUS_OK);
+    FinalizeSync(std::move(token), SYNC_STATUS_OK);
     return;
   }
 
   if (status != SYNC_STATUS_OK) {
-    FinalizeSync(token.Pass(), status);
+    FinalizeSync(std::move(token), status);
     return;
   }
 
   DCHECK(dirty_tracker_);
   DCHECK(remote_metadata_);
   DCHECK(remote_metadata_->has_details());
 
   FileDetails updated_details = remote_metadata_->details();
   if (!dirty_tracker_->active() ||
       HasDisabledAppRoot(metadata_database(), *dirty_tracker_)) {
     // Operations for an inactive tracker don't update file content.
     if (dirty_tracker_->has_synced_details())
       updated_details.set_md5(dirty_tracker_->synced_details().md5());
     if (!dirty_tracker_->active()) {
       // Keep missing true, as the change hasn't been synced to local.
       updated_details.clear_md5();
       updated_details.set_missing(true);
     }
   }
 
   status = metadata_database()->UpdateTracker(
       dirty_tracker_->tracker_id(), updated_details);
-  FinalizeSync(token.Pass(), status);
+  FinalizeSync(std::move(token), status);
 }
 
 void RemoteToLocalSyncer::FinalizeSync(scoped_ptr<SyncTaskToken> token,
                                        SyncStatusCode status) {
   if (prepared_) {
     remote_change_processor()->FinalizeRemoteSync(
         url_, false /* clear_local_change */,
         base::Bind(SyncTaskManager::NotifyTaskDone,
                    base::Passed(&token), status));
     return;
   }
 
-  SyncTaskManager::NotifyTaskDone(token.Pass(), status);
+  SyncTaskManager::NotifyTaskDone(std::move(token), status);
 }
 
 void RemoteToLocalSyncer::Prepare(const SyncStatusCallback& callback) {
   DCHECK(url_.is_valid());
   remote_change_processor()->PrepareForProcessRemoteChange(
       url_,
       base::Bind(&RemoteToLocalSyncer::DidPrepare,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback));
 }
@@ skipping 10 matching lines @@
 
   local_metadata_.reset(new SyncFileMetadata(local_metadata));
   local_changes_.reset(new FileChangeList(local_changes));
 
   callback.Run(status);
 }
 
 void RemoteToLocalSyncer::DeleteLocalFile(scoped_ptr<SyncTaskToken> token) {
   remote_change_processor()->ApplyRemoteChange(
       FileChange(FileChange::FILE_CHANGE_DELETE, SYNC_FILE_TYPE_UNKNOWN),
-      base::FilePath(),
-      url_,
-      SyncCompletedCallback(token.Pass()));
+      base::FilePath(), url_, SyncCompletedCallback(std::move(token)));
 }
 
 void RemoteToLocalSyncer::DownloadFile(scoped_ptr<SyncTaskToken> token) {
   DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 
   storage::ScopedFile file = CreateTemporaryFile(
       make_scoped_refptr(sync_context_->GetWorkerTaskRunner()));
 
   base::FilePath path = file.path();
   drive_service()->DownloadFile(
       path, remote_metadata_->file_id(),
       base::Bind(&RemoteToLocalSyncer::DidDownloadFile,
                  weak_ptr_factory_.GetWeakPtr(),
                  base::Passed(&token), base::Passed(&file)),
       google_apis::GetContentCallback(),
       google_apis::ProgressCallback());
 }
 
 void RemoteToLocalSyncer::DidDownloadFile(scoped_ptr<SyncTaskToken> token,
                                           storage::ScopedFile file,
                                           google_apis::DriveApiErrorCode error,
                                           const base::FilePath&) {
   DCHECK(sync_context_->GetWorkerTaskRunner()->RunsTasksOnCurrentThread());
 
   SyncStatusCode status = DriveApiErrorCodeToSyncStatusCode(error);
   if (status != SYNC_STATUS_OK) {
-    SyncCompleted(token.Pass(), status);
+    SyncCompleted(std::move(token), status);
     return;
   }
 
   base::FilePath path = file.path();
   const std::string md5 = drive::util::GetMd5Digest(path, nullptr);
   if (md5.empty()) {
-    SyncCompleted(token.Pass(), SYNC_FILE_ERROR_NOT_FOUND);
+    SyncCompleted(std::move(token), SYNC_FILE_ERROR_NOT_FOUND);
     return;
   }
 
   if (md5 != remote_metadata_->details().md5()) {
     // File has been modified since last metadata retrieval.
-    SyncCompleted(token.Pass(), SYNC_STATUS_RETRY);
+    SyncCompleted(std::move(token), SYNC_STATUS_RETRY);
     return;
   }
 
   remote_change_processor()->ApplyRemoteChange(
       FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE, SYNC_FILE_TYPE_FILE),
       path, url_,
       base::Bind(&RemoteToLocalSyncer::DidApplyDownload,
                  weak_ptr_factory_.GetWeakPtr(),
                  base::Passed(&token), base::Passed(&file)));
 }
 
 void RemoteToLocalSyncer::DidApplyDownload(scoped_ptr<SyncTaskToken> token,
                                            storage::ScopedFile,
                                            SyncStatusCode status) {
-  SyncCompleted(token.Pass(), status);
+  SyncCompleted(std::move(token), status);
 }
 
 void RemoteToLocalSyncer::CreateFolder(scoped_ptr<SyncTaskToken> token) {
   remote_change_processor()->ApplyRemoteChange(
       FileChange(FileChange::FILE_CHANGE_ADD_OR_UPDATE,
                  SYNC_FILE_TYPE_DIRECTORY),
-      base::FilePath(), url_,
-      SyncCompletedCallback(token.Pass()));
+      base::FilePath(), url_, SyncCompletedCallback(std::move(token)));
 }
 
 drive::DriveServiceInterface* RemoteToLocalSyncer::drive_service() {
   return sync_context_->GetDriveService();
 }
 
 MetadataDatabase* RemoteToLocalSyncer::metadata_database() {
   return sync_context_->GetMetadataDatabase();
 }
 
 RemoteChangeProcessor* RemoteToLocalSyncer::remote_change_processor() {
   DCHECK(sync_context_->GetRemoteChangeProcessor());
   return sync_context_->GetRemoteChangeProcessor();
 }
 
 SyncStatusCallback RemoteToLocalSyncer::SyncCompletedCallback(
     scoped_ptr<SyncTaskToken> token) {
   return base::Bind(&RemoteToLocalSyncer::SyncCompleted,
                     weak_ptr_factory_.GetWeakPtr(),
                     base::Passed(&token));
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system