Add support for uninstalling components and use it in SupervisedUserWhitelistInstaller.

chrome/browser/component_updater/pnacl/pnacl_component_installer.h

 // Copyright (c) 2011 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 CHROME_BROWSER_COMPONENT_UPDATER_PNACL_PNACL_COMPONENT_INSTALLER_H_
 #define CHROME_BROWSER_COMPONENT_UPDATER_PNACL_PNACL_COMPONENT_INSTALLER_H_
 
 #include <list>
 #include <string>
 
@@ skipping 25 matching lines @@
 
 // Component installer responsible for Portable Native Client files.
 // Files can be installed to a shared location, or be installed to
 // a per-user location.
 class PnaclComponentInstaller : public update_client::ComponentInstaller {
  public:
   PnaclComponentInstaller();
 
   // ComponentInstaller implementation:
   void OnUpdateError(int error) override;
-
   bool Install(const base::DictionaryValue& manifest,
                const base::FilePath& unpack_path) override;
-
   bool GetInstalledFile(const std::string& file,
                         base::FilePath* installed_file) override;
+  bool Uninstall() override;
 
   // Register a PNaCl component for the first time.
   void RegisterPnaclComponent(ComponentUpdateService* cus);
 
   update_client::CrxComponent GetCrxComponent();
 
   // Determine the base directory for storing each version of PNaCl.
   base::FilePath GetPnaclBaseDirectory();
 
   base::Version current_version() const { return current_version_; }
@@ skipping 16 matching lines @@
   base::Version current_version_;
   std::string current_fingerprint_;
   ComponentUpdateService* cus_;
 
   DISALLOW_COPY_AND_ASSIGN(PnaclComponentInstaller);
 };
 
 }  // namespace component_updater
 
 #endif  // CHROME_BROWSER_COMPONENT_UPDATER_PNACL_PNACL_COMPONENT_INSTALLER_H_