Sanitize PrefStore interface.

chrome/browser/policy/configuration_policy_pref_store.cc

 // Copyright (c) 2010 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/configuration_policy_pref_store.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/singleton.h"
@@ skipping 304 matching lines @@
 }
 
 ConfigurationPolicyPrefStore::ConfigurationPolicyPrefStore(
     ConfigurationPolicyProvider* provider)
     : provider_(provider),
       prefs_(new DictionaryValue()),
       lower_priority_proxy_settings_overridden_(false),
       proxy_disabled_(false),
       proxy_configuration_specified_(false),
       use_system_proxy_(false) {
+  if (!provider_->Provide(this))
+    LOG(WARNING) << "Failed to get policy from provider.";
+  FinalizeDefaultSearchPolicySettings();
 }
 
-PrefStore::PrefReadError ConfigurationPolicyPrefStore::ReadPrefs() {
-  proxy_disabled_ = false;
-  proxy_configuration_specified_ = false;
-  lower_priority_proxy_settings_overridden_ = false;
+PrefStore::ReadResult ConfigurationPolicyPrefStore::GetValue(
+    const std::string& key,
+    Value** value) const {
+  Value* configured_value = NULL;
+  if (!prefs_->Get(key, &configured_value) || !configured_value)
+    return READ_NO_VALUE;
 
-  const bool success = (provider_ == NULL || provider_->Provide(this));
-  FinalizeDefaultSearchPolicySettings();
-  return success ? PrefStore::PREF_READ_ERROR_NONE :
-      PrefStore::PREF_READ_ERROR_OTHER;
+  if (configured_value->IsType(Value::TYPE_NULL))
+    return READ_USE_DEFAULT;
+
+  *value = configured_value;
+  return READ_OK;
 }
 
 void ConfigurationPolicyPrefStore::Apply(ConfigurationPolicyType policy,
                                          Value* value) {
   if (ApplyProxyPolicy(policy, value))
     return;
 
   if (ApplySyncPolicy(policy, value))
     return;
 
@@ skipping 111 matching lines @@
   // proxy-related command-line switches or set proxy-related prefs in an
   // extension that are related, but not identical, to the ones set through
   // policy.
   if (!lower_priority_proxy_settings_overridden_ &&
       (match_entry ||
        policy == kPolicyProxyServerMode)) {
     ProxyPreferenceSet proxy_preference_set;
     GetProxyPreferenceSet(&proxy_preference_set);
     for (ProxyPreferenceSet::const_iterator i = proxy_preference_set.begin();
          i != proxy_preference_set.end(); ++i) {
-      prefs_->Set(*i, PrefStore::CreateUseDefaultSentinelValue());
+      prefs_->Set(*i, Value::CreateNullValue());

[danno, 2010/12/08 13:08:45]

Through comment or well named method it should be clear why it's OK to use the
Null in this store as a sentinel.

[Mattias Nissler (ping if slow), 2010/12/09 10:20:20]

Done.

     }
     lower_priority_proxy_settings_overridden_ = true;
   }
 
   // Translate the proxy policy into preferences.
   if (policy == kPolicyProxyServerMode) {
     int int_value;
     bool proxy_auto_detect = false;
     if (value->GetAsInteger(&int_value)) {
       result = true;
@@ skipping 165 matching lines @@
                         std::string());
       return;
     }
   }
   // Required entries are not there.  Remove any related entries.
   RemovePreferencesOfMap(kDefaultSearchPolicyMap,
                          arraysize(kDefaultSearchPolicyMap));
 }
 
 }  // namespace policy