Add support for uninstalling components and use it in SupervisedUserWhitelistInstaller.

components/component_updater/default_component_installer.cc

 // 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.
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/values.h"
 #include "base/version.h"
 // TODO(ddorwin): Find a better place for ReadManifest.
 #include "components/component_updater/component_updater_service.h"
 #include "components/component_updater/default_component_installer.h"
 #include "components/update_client/component_unpacker.h"
-#include "components/update_client/update_client.h"
+#include "components/update_client/utils.h"
 
 using update_client::CrxComponent;
 
 namespace component_updater {
 
 namespace {
+
 // Version "0" corresponds to no installed version. By the server's conventions,
 // we represent it as a dotted quad.
 const char kNullVersion[] = "0.0.0.0";
+
 }  // namespace
 
 ComponentInstallerTraits::~ComponentInstallerTraits() {
 }
 
 DefaultComponentInstaller::DefaultComponentInstaller(
     scoped_ptr<ComponentInstallerTraits> installer_traits)
     : current_version_(kNullVersion),
       main_task_runner_(base::MessageLoopProxy::current()) {
   installer_traits_ = installer_traits.Pass();
 }
 
 DefaultComponentInstaller::~DefaultComponentInstaller() {
-  DCHECK(thread_checker_.CalledOnValidThread());
 }
 
 void DefaultComponentInstaller::Register(ComponentUpdateService* cus) {
   DCHECK(thread_checker_.CalledOnValidThread());
   task_runner_ = cus->GetSequencedTaskRunner();
 
   if (!installer_traits_) {
     NOTREACHED() << "A DefaultComponentInstaller has been created but "
                  << "has no installer traits.";
     return;
@@ skipping 16 matching lines @@
     return false;
   if (!installer_traits_->OnCustomInstall(manifest, install_path))
     return false;
   if (!installer_traits_->VerifyInstallation(manifest, install_path))
     return false;
   return true;
 }
 
 bool DefaultComponentInstaller::Install(const base::DictionaryValue& manifest,
                                         const base::FilePath& unpack_path) {
+  DCHECK(task_runner_->RunsTasksOnCurrentThread());
+
   std::string manifest_version;
   manifest.GetStringASCII("version", &manifest_version);
   base::Version version(manifest_version.c_str());
   if (!version.IsValid())
     return false;
   if (current_version_.CompareTo(version) > 0)
     return false;
   base::FilePath install_path =
       installer_traits_->GetBaseDirectory().AppendASCII(version.GetString());
   if (base::PathExists(install_path)) {
@@ skipping 22 matching lines @@
     base::FilePath* installed_file) {
   if (current_version_.Equals(base::Version(kNullVersion)))
     return false;  // No component has been installed yet.
 
   *installed_file = installer_traits_->GetBaseDirectory()
                         .AppendASCII(current_version_.GetString())
                         .AppendASCII(file);
   return true;
 }
 
+bool DefaultComponentInstaller::Uninstall() {
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&DefaultComponentInstaller::UninstallOnTaskRunner, this));
+  return true;
+}
+
 void DefaultComponentInstaller::StartRegistration(ComponentUpdateService* cus) {
   DCHECK(task_runner_.get());
   DCHECK(task_runner_->RunsTasksOnCurrentThread());
   base::FilePath base_dir = installer_traits_->GetBaseDirectory();
   if (!base::PathExists(base_dir) && !base::CreateDirectory(base_dir)) {
     NOTREACHED() << "Could not create the base directory for "
                  << installer_traits_->GetName() << " ("
                  << base_dir.MaybeAsASCII() << ").";
     return;
   }
@@ skipping 57 matching lines @@
   // browser startup.
   for (const auto& older_path : older_paths)
     base::DeleteFile(older_path, true);
 
   main_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&DefaultComponentInstaller::FinishRegistration,
                  this, cus));
 }
 
+void DefaultComponentInstaller::UninstallOnTaskRunner() {
+  DCHECK(task_runner_.get());
+  DCHECK(task_runner_->RunsTasksOnCurrentThread());
+  const base::FilePath base_dir = installer_traits_->GetBaseDirectory();
+
+  base::FileEnumerator file_enumerator(base_dir, false,
+                                       base::FileEnumerator::DIRECTORIES);
+  for (base::FilePath path = file_enumerator.Next(); !path.value().empty();
+       path = file_enumerator.Next()) {
+    base::Version version(path.BaseName().MaybeAsASCII());
+
+    // Ignore folders that don't have valid version names. These folders are not
+    // managed by the component installer, so do not try to remove them.
+    if (!version.IsValid())
+      continue;
+
+    if (!base::DeleteFile(path, true))
+      DLOG(ERROR) << "Couldn't delete " << path.value();
+  }
+
+  // Delete the base directory if it's empty now.
+  if (base::IsDirectoryEmpty(base_dir)) {
+    if (base::DeleteFile(base_dir, false))
+      DLOG(ERROR) << "Couldn't delete " << base_dir.value();
+  }
+}
+
 base::FilePath DefaultComponentInstaller::GetInstallDirectory() {
   return installer_traits_->GetBaseDirectory()
       .AppendASCII(current_version_.GetString());
 }
 
 void DefaultComponentInstaller::FinishRegistration(
     ComponentUpdateService* cus) {
   DCHECK(thread_checker_.CalledOnValidThread());
   if (installer_traits_->CanAutoUpdate()) {
     CrxComponent crx;
@@ skipping 19 matching lines @@
   ComponentReady(manifest_copy.Pass());
 }
 
 void DefaultComponentInstaller::ComponentReady(
     scoped_ptr<base::DictionaryValue> manifest) {
   installer_traits_->ComponentReady(
       current_version_, GetInstallDirectory(), manifest.Pass());
 }
 
 }  // namespace component_updater