Add support for uninstalling components and use it in SupervisedUserWhitelistInstaller.

components/component_updater/component_updater_service.h

 // Copyright 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.
 
 #ifndef COMPONENTS_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
 #define COMPONENTS_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_
 
 #include <stdint.h>
 #include <string>
 #include <vector>
@@ skipping 106 matching lines @@
 
   // Stop doing update checks. In-flight requests and pending installations
   // will not be canceled.
   virtual Status Stop() = 0;
 
   // Add component to be checked for updates. You can call this method
   // before calling Start().
   virtual Status RegisterComponent(
       const update_client::CrxComponent& component) = 0;
 
+  // Unregisters the component with the given ID. This means that the component
+  // is not going to be included in future update checks. If a download or
+  // update operation for the component is currently in progress, it will
+  // silently finish without triggering the next step.
+  // Note that the installer for the component is responsible for removing any
+  // existing versions of the component from disk.
+  virtual Status UnregisterComponent(const std::string& crx_id) = 0;
+
   // Returns a list of registered components.
   virtual std::vector<std::string> GetComponentIDs() const = 0;
 
   // Returns an interface for on-demand updates. On-demand updates are
   // proactively triggered outside the normal component update service schedule.
   virtual OnDemandUpdater& GetOnDemandUpdater() = 0;
 
   // This method is used to trigger an on-demand update for component |crx_id|.
   // This can be used when loading a resource that depends on this component.
   //
@@ skipping 46 matching lines @@
 };
 
 // Creates the component updater. You must pass a valid |config| allocated on
 // the heap which the component updater will own.
 ComponentUpdateService* ComponentUpdateServiceFactory(
     update_client::Configurator* config);
 
 }  // namespace component_updater
 
 #endif  // COMPONENTS_COMPONENT_UPDATER_COMPONENT_UPDATER_SERVICE_H_