Fixed crash in CloudPolicyManager.

chrome/browser/policy/cloud/component_cloud_policy_service.cc

 // Copyright (c) 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/policy/cloud/component_cloud_policy_service.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 251 matching lines @@
   io_task_runner_->DeleteSoon(FROM_HERE,
                               external_policy_data_fetcher_backend_.release());
   backend_task_runner_->DeleteSoon(FROM_HERE, backend_.release());
 }
 
 // static
 bool ComponentCloudPolicyService::SupportsDomain(PolicyDomain domain) {
   return ComponentCloudPolicyStore::SupportsDomain(domain);
 }
 
+void ComponentCloudPolicyService::ClearCache() {
+  DCHECK(CalledOnValidThread());
+  // Empty credentials will wipe the cache.
+  backend_task_runner_->PostTask(FROM_HERE,
+                                 base::Bind(&Backend::SetCredentials,
+                                            base::Unretained(backend_.get()),
+                                            std::string(), std::string()));
+}
+
 void ComponentCloudPolicyService::OnSchemaRegistryReady() {
   DCHECK(CalledOnValidThread());
   InitializeIfReady();
 }
 
 void ComponentCloudPolicyService::OnSchemaRegistryUpdated(
     bool has_new_schemas) {
   DCHECK(CalledOnValidThread());
 
   // Ignore schema updates until the backend is initialized.
@@ skipping 215 matching lines @@
 }
 
 void ComponentCloudPolicyService::OnPolicyUpdated(
     scoped_ptr<PolicyBundle> policy) {
   DCHECK(CalledOnValidThread());
   policy_.Swap(policy.get());
   delegate_->OnComponentCloudPolicyUpdated();
 }
 
 }  // namespace policy