[SyncFS] Refine network error handling

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 "base/bind.h"
 #include "base/callback.h"
 #include "base/format_macros.h"
 #include "base/location.h"
@@ skipping 262 matching lines @@
 }
 
 void RemoteToLocalSyncer::HandleMissingRemoteMetadata(
     const SyncStatusCallback& callback) {
   DCHECK(dirty_tracker_);
 
   drive_service()->GetResourceEntry(
       dirty_tracker_->file_id(),
       base::Bind(&RemoteToLocalSyncer::DidGetRemoteMetadata,
                  weak_ptr_factory_.GetWeakPtr(),
-                 callback,
-                 metadata_database()->GetLargestKnownChangeID()));
+                 callback));
 }
 
 void RemoteToLocalSyncer::DidGetRemoteMetadata(
     const SyncStatusCallback& callback,
-    int64 change_id,
     google_apis::GDataErrorCode error,
     scoped_ptr<google_apis::ResourceEntry> entry) {
+  SyncStatusCode status = GDataErrorCodeToSyncStatusCode(error);
+  if (status != SYNC_STATUS_OK &&
+      error != google_apis::HTTP_NOT_FOUND) {
+    callback.Run(status);
+    return;
+  }
+
+  if (error == google_apis::HTTP_NOT_FOUND) {
+    metadata_database()->UpdateByDeletedRemoteFile(
+        dirty_tracker_->file_id(), callback);
+    return;
+  }
+
+  if (!entry) {
+    NOTREACHED();
+    callback.Run(SYNC_STATUS_FAILED);
+    return;
+  }
+
   metadata_database()->UpdateByFileResource(
       *drive::util::ConvertResourceEntryToFileResource(*entry),
       base::Bind(&RemoteToLocalSyncer::DidUpdateDatabaseForRemoteMetadata,
                  weak_ptr_factory_.GetWeakPtr(), callback));
 }
 
 void RemoteToLocalSyncer::DidUpdateDatabaseForRemoteMetadata(
     const SyncStatusCallback& callback,
     SyncStatusCode status) {
   if (status != SYNC_STATUS_OK) {
@@ skipping 209 matching lines @@
                  weak_ptr_factory_.GetWeakPtr(),
                  callback,
                  base::Passed(make_scoped_ptr(new FileIDList))));
 }
 
 void RemoteToLocalSyncer::DidListFolderContent(
     const SyncStatusCallback& callback,
     scoped_ptr<FileIDList> children,
     google_apis::GDataErrorCode error,
     scoped_ptr<google_apis::ResourceList> resource_list) {
-  if (error != google_apis::HTTP_SUCCESS) {
-    callback.Run(GDataErrorCodeToSyncStatusCode(error));
+  SyncStatusCode status = GDataErrorCodeToSyncStatusCode(error);
+  if (status != SYNC_STATUS_OK) {
+    callback.Run(status);
     return;
   }
 
+  if (!resource_list) {
+    NOTREACHED();
+    callback.Run(SYNC_STATUS_FAILED);
+    return;
+  }
+
   children->reserve(children->size() + resource_list->entries().size());
   for (ScopedVector<google_apis::ResourceEntry>::const_iterator itr =
            resource_list->entries().begin();
        itr != resource_list->entries().end();
        ++itr) {
     children->push_back((*itr)->resource_id());
   }
 
   GURL next_feed;
   if (resource_list->GetNextFeedURL(&next_feed)) {
@@ skipping 116 matching lines @@
                  weak_ptr_factory_.GetWeakPtr(),
                  callback, base::Passed(&file)),
       google_apis::GetContentCallback(),
       google_apis::ProgressCallback());
 }
 
 void RemoteToLocalSyncer::DidDownloadFile(const SyncStatusCallback& callback,
                                           webkit_blob::ScopedFile file,
                                           google_apis::GDataErrorCode error,
                                           const base::FilePath&) {
-  if (error != google_apis::HTTP_SUCCESS) {
-    callback.Run(GDataErrorCodeToSyncStatusCode(error));
+  SyncStatusCode status = GDataErrorCodeToSyncStatusCode(error);
+  if (status != SYNC_STATUS_OK) {
+    callback.Run(status);
     return;
   }
 
   base::FilePath path = file.path();
   base::PostTaskAndReplyWithResult(
       sync_context_->GetBlockingTaskRunner(), FROM_HERE,
       base::Bind(&drive::util::GetMd5Digest, path),
       base::Bind(&RemoteToLocalSyncer::DidCalculateMD5ForDownload,
                  weak_ptr_factory_.GetWeakPtr(),
                  callback, base::Passed(&file)));
@@ skipping 51 matching lines @@
   return sync_context_->GetMetadataDatabase();
 }
 
 RemoteChangeProcessor* RemoteToLocalSyncer::remote_change_processor() {
   DCHECK(sync_context_->GetRemoteChangeProcessor());
   return sync_context_->GetRemoteChangeProcessor();
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system