ServiceWorker: Print error message when failed to open diskcache

content/browser/service_worker/service_worker_storage.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 "content/browser/service_worker/service_worker_storage.h"
 
 #include <string>
 
 #include "base/bind_helpers.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 676 matching lines @@
       base::Bind(&ServiceWorkerStorage::OnDiskCacheInitialized,
                  weak_factory_.GetWeakPtr()));
   if (rv != net::ERR_IO_PENDING)
     OnDiskCacheInitialized(rv);
 
   return disk_cache_.get();
 }
 
 void ServiceWorkerStorage::OnDiskCacheInitialized(int rv) {
   if (rv != net::OK) {
-    LOG(ERROR) << "Failed to open the serviceworker diskcache.";
+    LOG(ERROR) << "Failed to open the serviceworker diskcache: "
+               << net::ErrorToString(rv);
     // TODO(michaeln): DeleteAndStartOver()
     disk_cache_->Disable();
     state_ = DISABLED;
   }
 }
 
 void ServiceWorkerStorage::StartPurgingResources(
     const std::vector<int64>& ids) {
   for (size_t i = 0; i < ids.size(); ++i)
     purgeable_reource_ids_.push_back(ids[i]);
@@ skipping 192 matching lines @@
     const FindInDBCallback& callback) {
   ServiceWorkerDatabase::RegistrationData data;
   ResourceList resources;
   ServiceWorkerDatabase::Status status =
       database->ReadRegistration(registration_id, origin, &data, &resources);
   original_task_runner->PostTask(
       FROM_HERE, base::Bind(callback, data, resources, status));
 }
 
 }  // namespace content