Work around CancelableCompletionCallback threading restrictions.

webkit/appcache/appcache_quota_client.cc

 // Copyright (c) 2011 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 "webkit/appcache/appcache_quota_client.h"
 
 #include <algorithm>
 #include <map>
 #include <set>
 
@@ skipping 16 matching lines @@
 void RunFront(appcache::AppCacheQuotaClient::RequestQueue* queue) {
   base::Closure request = queue->front();
   queue->pop_front();
   request.Run();
 }
 }  // namespace
 
 namespace appcache {
 
 AppCacheQuotaClient::AppCacheQuotaClient(AppCacheService* service)
-    : ALLOW_THIS_IN_INITIALIZER_LIST(service_delete_callback_(
-          base::Bind(&AppCacheQuotaClient::DidDeleteAppCachesForOrigin,
-                     base::Unretained(this)))),
-      service_(service),
+    : service_(service),
       appcache_is_ready_(false),
       quota_manager_is_destroyed_(false) {
 }
 
 AppCacheQuotaClient::~AppCacheQuotaClient() {
   DCHECK(pending_batch_requests_.empty());
   DCHECK(pending_serial_requests_.empty());
   DCHECK(current_delete_request_callback_.is_null());
 }
 
 QuotaClient::ID AppCacheQuotaClient::id() const {
   return kAppcache;
 }
 
 void AppCacheQuotaClient::OnQuotaManagerDestroyed() {
   DeletePendingRequests();
   if (!current_delete_request_callback_.is_null()) {
     current_delete_request_callback_.Reset();
-    service_delete_callback_.Cancel();
+    GetServiceDeleteCallback()->Cancel();
   }
 
   quota_manager_is_destroyed_ = true;
   if (!service_)
     delete this;
 }
 
 void AppCacheQuotaClient::GetOriginUsage(
     const GURL& origin,
     quota::StorageType type,
@@ skipping 62 matching lines @@
     return;
   }
 
   current_delete_request_callback_ = callback;
   if (type == quota::kStorageTypePersistent) {
     DidDeleteAppCachesForOrigin(net::OK);
     return;
   }
 
   service_->DeleteAppCachesForOrigin(
-      origin, service_delete_callback_.callback());
+      origin, GetServiceDeleteCallback()->callback());
 }
 
 void AppCacheQuotaClient::DidDeleteAppCachesForOrigin(int rv) {
   DCHECK(service_);
   if (quota_manager_is_destroyed_)
     return;
 
   // Finish the request by calling our callers callback.
   current_delete_request_callback_.Run(NetErrorCodeToQuotaStatus(rv));
   current_delete_request_callback_.Reset();
@@ skipping 50 matching lines @@
 void AppCacheQuotaClient::DeletePendingRequests() {
   pending_batch_requests_.clear();
   pending_serial_requests_.clear();
 }
 
 const AppCacheStorage::UsageMap* AppCacheQuotaClient::GetUsageMap() {
   DCHECK(service_);
   return service_->storage()->usage_map();
 }
 
+net::CancelableCompletionCallback*
+AppCacheQuotaClient::GetServiceDeleteCallback() {
+  // Lazily created due to CancelableCompletionCallback's threading
+  // restrictions, there is no way to detach from the thread created on.
+  if (!service_delete_callback_.get()) {
+    service_delete_callback_.reset(
+        new net::CancelableCompletionCallback(
+            base::Bind(&AppCacheQuotaClient::DidDeleteAppCachesForOrigin,
+                       base::Unretained(this))));
+  }
+  return service_delete_callback_.get();
+}
+
 void AppCacheQuotaClient::NotifyAppCacheReady() {
   appcache_is_ready_ = true;
   ProcessPendingRequests();
 }
 
 void AppCacheQuotaClient::NotifyAppCacheDestroyed() {
   service_ = NULL;
   while (!pending_batch_requests_.empty())
     RunFront(&pending_batch_requests_);
 
   while (!pending_serial_requests_.empty())
     RunFront(&pending_serial_requests_);
 
   if (!current_delete_request_callback_.is_null()) {
     current_delete_request_callback_.Run(quota::kQuotaErrorAbort);
     current_delete_request_callback_.Reset();
-    service_delete_callback_.Cancel();
+    GetServiceDeleteCallback()->Cancel();
   }
 
   if (quota_manager_is_destroyed_)
     delete this;
 }
 
 }  // namespace appcache