Refactor the UpdateEngine and its actions in the component updater.

components/update_client/update_client.h

 // Copyright 2015 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.
 
 #ifndef COMPONENTS_UPDATE_CLIENT_UPDATE_CLIENT_H_
 #define COMPONENTS_UPDATE_CLIENT_UPDATE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 125 matching lines @@
 class DictionaryValue;
 class FilePath;
 }
 
 namespace update_client {
 
 class Configurator;
 enum class Error;
 struct CrxUpdateItem;
 
+enum class ComponentState {
+  kNew,
+  kChecking,
+  kCanUpdate,
+  kDownloadingDiff,
+  kDownloading,
+  kDownloaded,
+  kUpdatingDiff,
+  kUpdating,
+  kUpdated,
+  kUpToDate,
+  kUpdateError,
+  kUninstalled,
+  kLastStatus
+};
+
 // Called when a non-blocking call in this module completes.
 using Callback = base::Callback<void(Error error)>;
 
 // Defines an interface for a generic CRX installer.
 class CrxInstaller : public base::RefCountedThreadSafe<CrxInstaller> {
  public:
   // Contains the result of the Install operation.
   struct Result {
     explicit Result(int error, int extended_error = 0)
         : error(error), extended_error(extended_error) {}
@@ skipping 89 matching lines @@
       base::Callback<void(const std::vector<std::string>& ids,
                           std::vector<CrxComponent>* components)>;
 
   // Defines an interface to observe the UpdateClient. It provides
   // notifications when state changes occur for the service itself or for the
   // registered CRXs.
   class Observer {
    public:
     enum class Events {
       // Sent before the update client does an update check.
-      COMPONENT_CHECKING_FOR_UPDATES,
+      COMPONENT_CHECKING_FOR_UPDATES = 1,
 
       // Sent when there is a new version of a registered CRX. After
       // the notification is sent the CRX will be downloaded unless the
       // update client inserts a
       COMPONENT_UPDATE_FOUND,
 
       // Sent when a CRX is in the update queue but it can't be acted on
       // right away, because the update client spaces out CRX updates due to a
       // throttling policy.
       COMPONENT_WAIT,
@@ skipping 90 matching lines @@
 scoped_refptr<UpdateClient> UpdateClientFactory(
     const scoped_refptr<Configurator>& config);
 
 // This must be called prior to the construction of any Configurator that
 // contains a PrefService.
 void RegisterPrefs(PrefRegistrySimple* registry);
 
 }  // namespace update_client
 
 #endif  // COMPONENTS_UPDATE_CLIENT_UPDATE_CLIENT_H_