Add support for uninstalling components and use it in SupervisedUserWhitelistInstaller.

chrome/browser/component_updater/swiftshader_component_installer.cc

 // Copyright (c) 2012 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/component_updater/swiftshader_component_installer.h"
 
 #include <stdint.h>
 #include <string>
 #include <vector>
 
@@ skipping 82 matching lines @@
 
 void RegisterSwiftShaderWithChrome(const base::FilePath& path) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   GpuDataManager::GetInstance()->RegisterSwiftShaderPath(path);
 }
 
 class SwiftShaderComponentInstaller : public update_client::ComponentInstaller {
  public:
   explicit SwiftShaderComponentInstaller(const Version& version);
 
-  ~SwiftShaderComponentInstaller() override {}
-
+  // 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;
 
  private:
+  ~SwiftShaderComponentInstaller() override {}
+
   Version current_version_;
 };
 
 SwiftShaderComponentInstaller::SwiftShaderComponentInstaller(
     const Version& version)
     : current_version_(version) {
   DCHECK(version.IsValid());
 }
 
 void SwiftShaderComponentInstaller::OnUpdateError(int error) {
@@ skipping 126 matching lines @@
 
 void RegisterSwiftShaderComponent(ComponentUpdateService* cus) {
 #if defined(ENABLE_SWIFTSHADER)
   BrowserThread::PostTask(BrowserThread::FILE,
                           FROM_HERE,
                           base::Bind(&RegisterSwiftShaderPath, cus));
 #endif
 }
 
 }  // namespace component_updater