Move preference MACs to the protected preference stores.

chrome/browser/prefs/tracked/dictionary_hash_store_contents.cc

+// Copyright (c) 2014 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/prefs/tracked/dictionary_hash_store_contents.h"
+
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/prefs/persistent_pref_store.h"
+#include "base/values.h"
+#include "chrome/common/pref_names.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+
+namespace {
+
+class SimpleMutableDictionary : public HashStoreContents::MutableDictionary {
+ public:
+  SimpleMutableDictionary(const std::string& key,
+                          base::DictionaryValue* storage);
+
+  // MutableDictionary implementation
+  virtual base::DictionaryValue* operator->() OVERRIDE;
+
+ private:
+  const std::string key_;
+  base::DictionaryValue* storage_;
+};
+
+SimpleMutableDictionary::SimpleMutableDictionary(const std::string& key,

[gab, 2014/06/13 01:57:43]

This is only used for the kProfilePreferenceHashes pref. I think it's overkill
to make this generic here.

I suggest removing the |key_| member and hardcoding kProfilePreferenceHashes
instead below.

(and renaming this class to e.g., MutablePreferencesHashesDictionary)

[erikwright (departed), 2014/06/16 20:51:27]

The flexibility was a remnant from a previous incarnation. Thanks.

+                                                 base::DictionaryValue* storage)
+    : key_(key), storage_(storage) {
+}
+
+base::DictionaryValue* SimpleMutableDictionary::operator->() {
+  base::DictionaryValue* mac_dictionary = NULL;
+
+  if (!storage_->GetDictionary(key_, &mac_dictionary)) {
+    mac_dictionary = new base::DictionaryValue;
+    storage_->Set(key_, mac_dictionary);
+  }
+
+  return mac_dictionary;
+}
+
+const base::DictionaryValue* GetMacDictionary(
+    const base::DictionaryValue* storage) {

[gab, 2014/06/13 01:57:43]

Since this method needs access to the only member of
DictionaryHashStoreContents, how about simply making it a private method?

[erikwright (departed), 2014/06/16 20:51:27]

Done.

+  const base::DictionaryValue* mac_dictionary = NULL;
+  storage->GetDictionary(prefs::kProfilePreferenceHashes, &mac_dictionary);
+  return mac_dictionary;
+}
+
+}  // namespace
+
+// static
+const char DictionaryHashStoreContents::kSuperMacPref[] = "super_mac";
+
+DictionaryHashStoreContents::DictionaryHashStoreContents(
+    base::DictionaryValue* storage)
+    : storage_(storage) {
+}
+
+// static
+void DictionaryHashStoreContents::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterDictionaryPref(
+      prefs::kProfilePreferenceHashes,

[gab, 2014/06/13 01:57:43]

In fact, how about using a new pref altogether, e.g. kPreferenceMACs?

It's our one-time opportunity at renaming everything (renaming the variables and
classes is easily done later, but renaming on-disk state, not so much).

[erikwright (departed), 2014/06/16 20:51:27]

Done.

+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+  registry->RegisterStringPref(
+      kSuperMacPref,
+      std::string(),
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+}
+
+std::string DictionaryHashStoreContents::hash_store_id() const {
+  return "";
+}
+
+void DictionaryHashStoreContents::Reset() {
+  storage_->Remove(prefs::kProfilePreferenceHashes, NULL);
+}
+
+bool DictionaryHashStoreContents::IsInitialized() const {
+  return storage_->GetDictionary(prefs::kProfilePreferenceHashes, NULL);
+}
+
+const base::DictionaryValue* DictionaryHashStoreContents::GetContents() const {
+  return GetMacDictionary(storage_);
+}
+
+scoped_ptr<HashStoreContents::MutableDictionary>
+DictionaryHashStoreContents::GetMutableContents() {
+  return scoped_ptr<MutableDictionary>(
+      new SimpleMutableDictionary(prefs::kProfilePreferenceHashes, storage_));
+}
+
+std::string DictionaryHashStoreContents::GetSuperMac() const {
+  std::string super_mac_string;
+  storage_->GetString(kSuperMacPref, &super_mac_string);
+  return super_mac_string;
+}
+
+void DictionaryHashStoreContents::SetSuperMac(const std::string& super_mac) {
+  storage_->SetString(kSuperMacPref, super_mac);
+}