Add the Sync.Attachments.StoreInitResult histogram.

sync/internal_api/attachments/on_disk_attachment_store.cc

 // Copyright 2014 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 "sync/internal_api/public/attachments/on_disk_attachment_store.h"
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/location.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram.h"
 #include "base/sequenced_task_runner.h"
 #include "sync/internal_api/attachments/proto/attachment_store.pb.h"
 #include "sync/internal_api/public/attachments/attachment_util.h"
 #include "sync/protocol/attachments.pb.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
 #include "third_party/leveldatabase/src/include/leveldb/options.h"
 #include "third_party/leveldatabase/src/include/leveldb/slice.h"
 #include "third_party/leveldatabase/src/include/leveldb/status.h"
 #include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
 
@@ skipping 64 matching lines @@
     const base::FilePath& path)
     : callback_task_runner_(callback_task_runner), path_(path) {
 }
 
 OnDiskAttachmentStore::~OnDiskAttachmentStore() {
 }
 
 void OnDiskAttachmentStore::Init(const InitCallback& callback) {
   DCHECK(CalledOnValidThread());
   Result result_code = OpenOrCreate(path_);
+  UMA_HISTOGRAM_ENUMERATION("Sync.Attachments.StoreInitResult",
+                            result_code, RESULT_SIZE);
   callback_task_runner_->PostTask(FROM_HERE, base::Bind(callback, result_code));
 }
 
 void OnDiskAttachmentStore::Read(const AttachmentIdList& ids,
                                  const ReadCallback& callback) {
   DCHECK(CalledOnValidThread());
   scoped_ptr<AttachmentMap> result_map(new AttachmentMap());
   scoped_ptr<AttachmentIdList> unavailable_attachments(new AttachmentIdList());
 
   Result result_code = STORE_INITIALIZATION_FAILED;
@@ skipping 286 matching lines @@
   return key;
 }
 
 AttachmentMetadata OnDiskAttachmentStore::MakeAttachmentMetadata(
     const AttachmentId& attachment_id,
     const attachment_store_pb::RecordMetadata& record_metadata) {
   return AttachmentMetadata(attachment_id, record_metadata.attachment_size());
 }
 
 }  // namespace syncer