Trigger chrome.storage.onChanged events for policy updates on the 'managed' namespace.

chrome/browser/extensions/settings/managed_value_store_cache.cc

 // Copyright (c) 2012 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/extensions/settings/managed_value_store_cache.h"
 
+#include <set>
+
 #include "base/logging.h"
 #include "base/message_loop_proxy.h"
 #include "base/sequenced_task_runner.h"
-#include "chrome/browser/policy/policy_service.h"
 #include "chrome/browser/value_store/policy_value_store.h"
+#include "chrome/browser/value_store/value_store_change.h"
 #include "chrome/common/extensions/extension.h"
 #include "content/public/browser/browser_thread.h"
 
 using content::BrowserThread;
 
 namespace extensions {
 
 ManagedValueStoreCache::ManagedValueStoreCache(
-    policy::PolicyService* policy_service)
-    : policy_service_(policy_service) {}
+    policy::PolicyService* policy_service,
+    scoped_refptr<SettingsObserverList> observers)
+    : policy_service_(policy_service),
+      observers_(observers) {
+  policy_service_->AddObserver(policy::POLICY_DOMAIN_EXTENSIONS, this);
+}
 
 ManagedValueStoreCache::~ManagedValueStoreCache() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  policy_service_->RemoveObserver(policy::POLICY_DOMAIN_EXTENSIONS, this);
 }
 
 scoped_refptr<base::MessageLoopProxy>
     ManagedValueStoreCache::GetMessageLoop() const {
   return BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI);
 }
 
 void ManagedValueStoreCache::RunWithValueStoreForExtension(
     const StorageCallback& callback,
     scoped_refptr<const Extension> extension) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   const policy::PolicyMap& policies = policy_service_->GetPolicies(
       policy::POLICY_DOMAIN_EXTENSIONS, extension->id());
   PolicyValueStore store(&policies);
   callback.Run(&store);
 }
 
 void ManagedValueStoreCache::DeleteStorageSoon(
     const std::string& extension_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   // There's no real storage backing this cache, so this is a nop.
 }
 
+void ManagedValueStoreCache::OnPolicyUpdated(policy::PolicyDomain domain,
+                                             const std::string& component_id,
+                                             const policy::PolicyMap& previous,
+                                             const policy::PolicyMap& current) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  ValueStoreChangeList changes;
+  std::set<std::string> changed_keys;
+  previous.GetDifferingKeys(current, &changed_keys);
+  for (std::set<std::string>::iterator it = changed_keys.begin();
+       it != changed_keys.end(); ++it) {
+    // A policy might've changed only its scope or level, while the value
+    // stayed the same. Events should be triggered only for mandatory values
+    // that have changed.
+    const policy::PolicyMap::Entry* old_entry = previous.Get(*it);
+    const policy::PolicyMap::Entry* new_entry = current.Get(*it);
+    scoped_ptr<base::Value> old_value;
+    scoped_ptr<base::Value> new_value;
+    if (old_entry && old_entry->level == policy::POLICY_LEVEL_MANDATORY)
+      old_value.reset(old_entry->value->DeepCopy());
+    if (new_entry && new_entry->level == policy::POLICY_LEVEL_MANDATORY)
+      new_value.reset(new_entry->value->DeepCopy());
+    if (!base::Value::Equals(old_value.get(), new_value.get())) {
+      changes.push_back(
+          ValueStoreChange(*it, old_value.release(), new_value.release()));
+    }
+  }
+  observers_->Notify(
+      &SettingsObserver::OnSettingsChanged,
+      component_id,
+      settings_namespace::MANAGED,
+      ValueStoreChange::ToJson(changes));
+}
+
 }  // namespace extensions