Integrate registry_hash_store_contents with the rest of tracked prefs.

components/user_prefs/tracked/registry_hash_store_contents_win.cc

Index: components/user_prefs/tracked/registry_hash_store_contents_win.cc
diff --git a/components/user_prefs/tracked/registry_hash_store_contents_win.cc b/components/user_prefs/tracked/registry_hash_store_contents_win.cc
index 9d8dcbdeb58639c4c53cd20e0a140ff86c2f5005..00ea014711f38dae81c39bd3a746b8635777245d 100644
--- a/components/user_prefs/tracked/registry_hash_store_contents_win.cc
+++ b/components/user_prefs/tracked/registry_hash_store_contents_win.cc
@@ -18,7 +18,7 @@ using base::win::RegistryValueIterator;
 
 namespace {
 
-constexpr size_t kMacSize = 32;
+constexpr size_t kMacSize = 64;
 
 base::string16 GetSplitPrefKeyName(const base::string16& reg_key_name,
                                    const std::string& split_key_name) {
@@ -72,6 +72,10 @@ RegistryHashStoreContentsWin::RegistryHashStoreContentsWin(
     : preference_key_name_(registry_path + L"\\PreferenceMACs\\" +
                            profile_name) {}
 
+HashStoreContentsType RegistryHashStoreContentsWin::GetType() const {
+  return HashStoreContentsType::REGISTRY_HASH_STORE_CONTENTS;
+}
+
 void RegistryHashStoreContentsWin::Reset() {
   base::win::RegKey key;
   if (key.Open(HKEY_CURRENT_USER, preference_key_name_.c_str(),
@@ -137,7 +141,6 @@ void RegistryHashStoreContentsWin::SetSplitMac(const std::string& path,
 }
 
 bool RegistryHashStoreContentsWin::RemoveEntry(const std::string& path) {
-  // ClearSplitMac is first to avoid short-circuit issues.
   return ClearAtomicMac(preference_key_name_, path) ||
          ClearSplitMac(preference_key_name_, path);
 }
@@ -145,22 +148,22 @@ bool RegistryHashStoreContentsWin::RemoveEntry(const std::string& path) {
 void RegistryHashStoreContentsWin::ImportEntry(const std::string& path,
                                                const base::Value* in_value) {
   NOTREACHED()
-      << "RegistryHashStore does not support the ImportEntry operation";
+      << "RegistryHashStoreContents does not support the ImportEntry operation";
 }
 
 const base::DictionaryValue* RegistryHashStoreContentsWin::GetContents() const {
   NOTREACHED()
-      << "RegistryHashStore does not support the GetContents operation";
+      << "RegistryHashStoreContents does not support the GetContents operation";
   return NULL;
 }
 
 std::string RegistryHashStoreContentsWin::GetSuperMac() const {
   NOTREACHED()
-      << "RegistryHashStore does not support the GetSuperMac operation";
+      << "RegistryHashStoreContents does not support the GetSuperMac operation";
   return NULL;
 }
 
 void RegistryHashStoreContentsWin::SetSuperMac(const std::string& super_mac) {
   NOTREACHED()
-      << "RegistryHashStore does not support the SetSuperMac operation";
+      << "RegistryHashStoreContents does not support the SetSuperMac operation";
 }