Refactor the UpdateEngine and its actions in the component updater.

components/update_client/component.cc

Index: components/update_client/component.cc
diff --git a/components/update_client/component.cc b/components/update_client/component.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f63b3c7e7a87aa9f610249e46b1ed412e1467f2a
--- /dev/null
+++ b/components/update_client/component.cc
@@ -0,0 +1,701 @@
+// Copyright 2017 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 "components/update_client/component.h"
+
+#include <algorithm>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/files/file_util.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "components/update_client/configurator.h"
+#include "components/update_client/update_client.h"
+#include "components/update_client/update_client_errors.h"
+#include "components/update_client/update_engine.h"
+#include "components/update_client/utils.h"
+
+// The state machine representing how a CRX component changes during an update.
+//
+//
+//                  on-demand                on-demand
+//   +--------------------------> kNew <---------------+-------------+
+//   |                              |                  |             |
+//   |                              V                  |             |
+//   |   +---------------0----> kChecking -<-------+---|---<-----+   |
+//   |   |                          |              |   |         |   |
+//   |   |            error         V       no     |   |         |   |
+//  kUpdateError <------------- [update?] ->---- kUpToDate     kUpdated
+//     ^                            |                              ^
+//     |                        yes |                              |
+//     |                            V                              |
+//     |                        kCanUpdate                         |
+//     |                            |                              |
+//     |                            V              no              |
+//     |                 [differential update?]--->----+           |
+//     |                            |                  |           |
+//     |                        yes |                  |           |
+//     |                            V          error   |           |
+//     |                 kDownloadingDiff --->---------+           |
+//     |                            |                  |           |
+//     |                            |                  |           |
+//     |                            V          error   |           |
+//     |                     kUpdatingDiff --->--------+-----------+ success
+//     |                                               |           |
+//     |              error                            V           |
+//     +----------------------------------------- kDownloading     |
+//     |                                               |           |
+//     |              error                            V           |
+//     +------------------------------------------ kUpdating ->----+ success
+
+namespace update_client {
+
+namespace {
+
+using InstallOnBlockingTaskRunnerCompleteCallback =
+    base::Callback<void(int error_category, int error_code, int extra_code1)>;
+
+CrxInstaller::Result DoInstallOnBlockingTaskRunner(
+    const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
+    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
+    const base::FilePath& unpack_path,
+    const std::string& fingerprint,
+    const scoped_refptr<CrxInstaller>& installer,
+    InstallOnBlockingTaskRunnerCompleteCallback callback) {
+  DCHECK(blocking_task_runner->RunsTasksOnCurrentThread());
+
+  if (static_cast<int>(fingerprint.size()) !=
+      base::WriteFile(
+          unpack_path.Append(FILE_PATH_LITERAL("manifest.fingerprint")),
+          fingerprint.c_str(), base::checked_cast<int>(fingerprint.size()))) {
+    return CrxInstaller::Result(InstallError::FINGERPRINT_WRITE_FAILED);
+  }
+
+  std::unique_ptr<base::DictionaryValue> manifest = ReadManifest(unpack_path);
+  if (!manifest)
+    return CrxInstaller::Result(InstallError::BAD_MANIFEST);
+
+  return installer->Install(*manifest, unpack_path);
+}
+
+void InstallOnBlockingTaskRunner(
+    const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
+    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
+    const base::FilePath& unpack_path,
+    const std::string& fingerprint,
+    const scoped_refptr<CrxInstaller>& installer,
+    InstallOnBlockingTaskRunnerCompleteCallback callback) {
+  DCHECK(blocking_task_runner->RunsTasksOnCurrentThread());
+
+  const auto result = DoInstallOnBlockingTaskRunner(
+      main_task_runner, blocking_task_runner, unpack_path, fingerprint,
+      installer, callback);
+
+  const ErrorCategory error_category =
+      result.error ? ErrorCategory::kInstallError : ErrorCategory::kErrorNone;
+  main_task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(callback, static_cast<int>(error_category),
+                 static_cast<int>(result.error), result.extended_error));
+}
+
+void UnpackCompleteOnBlockingTaskRunner(
+    const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
+    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
+    const base::FilePath& crx_path,
+    const std::string& fingerprint,
+    const scoped_refptr<CrxInstaller>& installer,
+    InstallOnBlockingTaskRunnerCompleteCallback callback,
+    const ComponentUnpacker::Result& result) {
+  DCHECK(blocking_task_runner->RunsTasksOnCurrentThread());
+
+  update_client::DeleteFileAndEmptyParentDirectory(crx_path);
+
+  if (result.error != UnpackerError::kNone) {
+    main_task_runner->PostTask(
+        FROM_HERE,
+        base::Bind(callback, static_cast<int>(ErrorCategory::kUnpackError),
+                   static_cast<int>(result.error), result.extended_error));
+    return;
+  }
+
+  blocking_task_runner->PostTask(
+      FROM_HERE, base::Bind(&InstallOnBlockingTaskRunner, main_task_runner,
+                            blocking_task_runner, result.unpack_path,
+                            fingerprint, installer, callback));
+}
+
+void StartInstallOnBlockingTaskRunner(
+    const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
+    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner,
+    const std::vector<uint8_t>& pk_hash,
+    const base::FilePath& crx_path,
+    const std::string& fingerprint,
+    const scoped_refptr<CrxInstaller>& installer,
+    const scoped_refptr<OutOfProcessPatcher>& oop_patcher,
+    InstallOnBlockingTaskRunnerCompleteCallback callback) {
+  DCHECK(blocking_task_runner->RunsTasksOnCurrentThread());
+
+  auto unpacker = base::MakeShared<ComponentUnpacker>(
+      pk_hash, crx_path, installer, oop_patcher, blocking_task_runner);
+
+  unpacker->Unpack(base::Bind(&UnpackCompleteOnBlockingTaskRunner,
+                              main_task_runner, blocking_task_runner, crx_path,
+                              fingerprint, installer, callback));
+}
+
+}  // namespace
+
+Component::Component(const UpdateContext& update_context, const std::string& id)
+    : id_(id),
+      state_(base::MakeUnique<StateNew>(this)),
+      update_context_(update_context) {}
+
+Component::~Component() {}
+
+void Component::Handle(CallbackHandleComplete callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(state_);
+
+  callback_handle_complete_ = callback;
+
+  state_->Handle(base::Bind(&Component::ChangeState, base::Unretained(this)));
+}
+
+void Component::ChangeState(std::unique_ptr<State> next_state) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (next_state)
+    state_ = std::move(next_state);
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
+                                                callback_handle_complete_);
+}
+
+CrxUpdateItem Component::GetCrxUpdateItem() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  CrxUpdateItem crx_update_item;
+  crx_update_item.state = state_->state();
+  crx_update_item.id = id_;
+  crx_update_item.component = crx_component_;
+  crx_update_item.last_check = last_check_;
+  crx_update_item.next_version = next_version_;
+  crx_update_item.next_fp = next_fp_;
+
+  return crx_update_item;
+}
+
+void Component::SetParseResult(const UpdateResponse::Result& result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  DCHECK_EQ(0, update_check_error_);
+
+  status_ = result.status;
+
+  if (result.manifest.packages.empty())
+    return;
+
+  next_version_ = base::Version(result.manifest.version);
+  const auto& package = result.manifest.packages.front();
+  next_fp_ = package.fingerprint;
+
+  // Resolve the urls by combining the base urls with the package names.
+  for (const auto& crx_url : result.crx_urls) {
+    const GURL url = crx_url.Resolve(package.name);
+    if (url.is_valid())
+      crx_urls_.push_back(url);
+  }
+  for (const auto& crx_diffurl : result.crx_diffurls) {
+    const GURL url = crx_diffurl.Resolve(package.namediff);
+    if (url.is_valid())
+      crx_diffurls_.push_back(url);
+  }
+
+  hash_sha256_ = package.hash_sha256;
+  hashdiff_sha256_ = package.hashdiff_sha256;
+}
+
+void Component::Uninstall(const base::Version& version, int reason) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  DCHECK_EQ(ComponentState::kNew, state());
+
+  previous_version_ = version;
+  next_version_ = base::Version("0");
+  extra_code1_ = reason;
+
+  state_ = base::MakeUnique<StateUninstalled>(this);
+}
+
+void Component::UpdateCheckComplete() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  DCHECK_EQ(ComponentState::kChecking, state());
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
+                                                update_check_complete_);
+}
+
+bool Component::CanDoBackgroundDownload() const {
+  // On demand component updates are always downloaded in foreground.
+  return !on_demand_ && crx_component_.allows_background_download &&
+         update_context_.config->EnabledBackgroundDownloader();
+}
+
+void Component::AppendDownloadMetrics(
+    const std::vector<CrxDownloader::DownloadMetrics>& download_metrics) {
+  download_metrics_.insert(download_metrics_.end(), download_metrics.begin(),
+                           download_metrics.end());
+}
+
+void Component::NotifyObservers(UpdateClient::Observer::Events event) const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  update_context_.notify_observers_callback.Run(event, id_);
+}
+
+base::TimeDelta Component::GetUpdateDuration() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (update_begin_.is_null())
+    return base::TimeDelta();
+
+  const base::TimeDelta update_cost(base::TimeTicks::Now() - update_begin_);
+  DCHECK_GE(update_cost, base::TimeDelta());
+  const base::TimeDelta max_update_delay =
+      base::TimeDelta::FromSeconds(update_context_.config->UpdateDelay());
+  return std::min(update_cost, max_update_delay);
+}
+
+Component::State::State(Component* component, ComponentState state)
+    : state_(state), component_(*component) {}
+
+Component::State::~State() {}
+
+void Component::State::Handle(CallbackNextState callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  callback_ = callback;
+
+  DCHECK(!is_final_);
+  DoHandle();
+}
+
+void Component::State::TransitionState(std::unique_ptr<State> next_state) {
+  if (!next_state)
+    is_final_ = true;
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback(), base::Passed(&next_state)));
+}
+
+Component::StateNew::StateNew(Component* component)
+    : State(component, ComponentState::kNew) {}
+
+Component::StateNew::~StateNew() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateNew::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = State::component();
+
+  TransitionState(base::MakeUnique<StateChecking>(&component));
+}
+
+Component::StateChecking::StateChecking(Component* component)
+    : State(component, ComponentState::kChecking) {}
+
+Component::StateChecking::~StateChecking() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+// Unlike how other states are handled, this function does not change the
+// state right away. The state transition happens when the UpdateChecker
+// calls Component::UpdateCheckComplete and |update_check_complete_| is invoked.
+// This is an artifact of how multiple components must be checked for updates
+// together but the state machine defines the transitions for one component
+// at a time.
+void Component::StateChecking::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = State::component();
+
+  component.last_check_ = base::TimeTicks::Now();
+  component.update_check_complete_ = base::Bind(
+      &Component::StateChecking::UpdateCheckComplete, base::Unretained(this));
+
+  component.NotifyObservers(Events::COMPONENT_CHECKING_FOR_UPDATES);
+}
+
+void Component::StateChecking::UpdateCheckComplete() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  auto& component = State::component();
+  if (!component.update_check_error_) {
+    if (component.status_ == "ok") {
+      TransitionState(base::MakeUnique<StateCanUpdate>(&component));
+      return;
+    }
+
+    if (component.status_ == "noupdate") {
+      TransitionState(base::MakeUnique<StateUpToDate>(&component));
+      return;
+    }
+  }
+
+  TransitionState(base::MakeUnique<StateUpdateError>(&component));
+}
+
+Component::StateUpdateError::StateUpdateError(Component* component)
+    : State(component, ComponentState::kUpdateError) {}
+
+Component::StateUpdateError::~StateUpdateError() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateUpdateError::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = State::component();
+  TransitionState(nullptr);
+  component.NotifyObservers(Events::COMPONENT_NOT_UPDATED);
+}
+
+Component::StateCanUpdate::StateCanUpdate(Component* component)
+    : State(component, ComponentState::kCanUpdate) {}
+
+Component::StateCanUpdate::~StateCanUpdate() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateCanUpdate::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = State::component();
+
+  component.is_update_available_ = true;
+  component.NotifyObservers(Events::COMPONENT_UPDATE_FOUND);
+
+  if (component.crx_component_.supports_group_policy_enable_component_updates &&
+      !component.update_context_.enabled_component_updates) {
+    component.error_category_ = static_cast<int>(ErrorCategory::kServiceError);
+    component.error_code_ = static_cast<int>(ServiceError::UPDATE_DISABLED);
+    component.extra_code1_ = 0;
+    TransitionState(base::MakeUnique<StateUpdateError>(&component));
+    return;
+  }
+
+  // Start computing the cost of the this update from here on.
+  component.update_begin_ = base::TimeTicks::Now();
+
+  if (CanTryDiffUpdate())
+    TransitionState(base::MakeUnique<StateDownloadingDiff>(&component));
+  else
+    TransitionState(base::MakeUnique<StateDownloading>(&component));
+}
+
+// Returns true if a differential update is available, it has not failed yet,
+// and the configuration allows this update.
+bool Component::StateCanUpdate::CanTryDiffUpdate() const {
+  const auto& component = Component::State::component();
+  return HasDiffUpdate(component) && !component.diff_error_code_ &&
+         component.update_context_.config->EnabledDeltas();
+}
+
+Component::StateUpToDate::StateUpToDate(Component* component)
+    : State(component, ComponentState::kUpToDate) {}
+
+Component::StateUpToDate::~StateUpToDate() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateUpToDate::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = State::component();
+
+  TransitionState(nullptr);
+  component.NotifyObservers(Events::COMPONENT_NOT_UPDATED);
+}
+
+Component::StateDownloadingDiff::StateDownloadingDiff(Component* component)
+    : State(component, ComponentState::kDownloadingDiff) {}
+
+Component::StateDownloadingDiff::~StateDownloadingDiff() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateDownloadingDiff::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& component = Component::State::component();
+  const auto& update_context = component.update_context_;
+
+  crx_downloader_ = update_context.crx_downloader_factory(
+      component.CanDoBackgroundDownload(),
+      update_context.config->RequestContext(),
+      update_context.blocking_task_runner);
+
+  const auto& id = component.id_;
+  crx_downloader_->set_progress_callback(
+      base::Bind(&Component::StateDownloadingDiff::DownloadProgress,
+                 base::Unretained(this), id));
+  crx_downloader_->StartDownload(
+      component.crx_diffurls_, component.hashdiff_sha256_,
+      base::Bind(&Component::StateDownloadingDiff::DownloadComplete,
+                 base::Unretained(this), id));
+
+  component.NotifyObservers(Events::COMPONENT_UPDATE_DOWNLOADING);
+}
+
+// Called when progress is being made downloading a CRX. The progress may
+// not monotonically increase due to how the CRX downloader switches between
+// different downloaders and fallback urls.
+void Component::StateDownloadingDiff::DownloadProgress(
+    const std::string& id,
+    const CrxDownloader::Result& download_result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  component().NotifyObservers(Events::COMPONENT_UPDATE_DOWNLOADING);
+}
+
+void Component::StateDownloadingDiff::DownloadComplete(
+    const std::string& id,
+    const CrxDownloader::Result& download_result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = Component::State::component();
+
+  component.AppendDownloadMetrics(crx_downloader_->download_metrics());
+
+  crx_downloader_.reset();
+
+  if (download_result.error) {
+    component.diff_error_category_ =
+        static_cast<int>(ErrorCategory::kNetworkError);
+    component.diff_error_code_ = download_result.error;
+
+    TransitionState(base::MakeUnique<StateDownloading>(&component));
+    return;
+  }
+
+  component.crx_path_ = download_result.response;
+
+  TransitionState(base::MakeUnique<StateUpdatingDiff>(&component));
+}
+
+Component::StateDownloading::StateDownloading(Component* component)
+    : State(component, ComponentState::kDownloading) {}
+
+Component::StateDownloading::~StateDownloading() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateDownloading::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& component = Component::State::component();
+  const auto& update_context = component.update_context_;
+
+  crx_downloader_ = update_context.crx_downloader_factory(
+      component.CanDoBackgroundDownload(),
+      update_context.config->RequestContext(),
+      update_context.blocking_task_runner);
+
+  const auto& id = component.id_;
+  crx_downloader_->set_progress_callback(
+      base::Bind(&Component::StateDownloading::DownloadProgress,
+                 base::Unretained(this), id));
+  crx_downloader_->StartDownload(
+      component.crx_urls_, component.hash_sha256_,
+      base::Bind(&Component::StateDownloading::DownloadComplete,
+                 base::Unretained(this), id));
+
+  component.NotifyObservers(Events::COMPONENT_UPDATE_DOWNLOADING);
+}
+
+// Called when progress is being made downloading a CRX. The progress may
+// not monotonically increase due to how the CRX downloader switches between
+// different downloaders and fallback urls.
+void Component::StateDownloading::DownloadProgress(
+    const std::string& id,
+    const CrxDownloader::Result& download_result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  component().NotifyObservers(Events::COMPONENT_UPDATE_DOWNLOADING);
+}
+
+void Component::StateDownloading::DownloadComplete(
+    const std::string& id,
+    const CrxDownloader::Result& download_result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = Component::State::component();
+
+  component.AppendDownloadMetrics(crx_downloader_->download_metrics());
+
+  crx_downloader_.reset();
+
+  if (download_result.error) {
+    component.error_category_ = static_cast<int>(ErrorCategory::kNetworkError);
+    component.error_code_ = download_result.error;
+
+    TransitionState(base::MakeUnique<StateUpdateError>(&component));
+    return;
+  }
+
+  component.crx_path_ = download_result.response;
+
+  TransitionState(base::MakeUnique<StateUpdating>(&component));
+}
+
+Component::StateUpdatingDiff::StateUpdatingDiff(Component* component)
+    : State(component, ComponentState::kUpdatingDiff) {}
+
+Component::StateUpdatingDiff::~StateUpdatingDiff() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateUpdatingDiff::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& component = Component::State::component();
+  const auto& update_context = component.update_context_;
+
+  component.NotifyObservers(Events::COMPONENT_UPDATE_READY);
+
+  update_context.blocking_task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(&update_client::StartInstallOnBlockingTaskRunner,
+                 base::ThreadTaskRunnerHandle::Get(),
+                 update_context.blocking_task_runner,
+                 component.crx_component_.pk_hash, component.crx_path_,
+                 component.next_fp_, component.crx_component_.installer,
+                 update_context.config->CreateOutOfProcessPatcher(),
+                 base::Bind(&Component::StateUpdatingDiff::InstallComplete,
+                            base::Unretained(this))));
+}
+
+void Component::StateUpdatingDiff::InstallComplete(int error_category,
+                                                   int error_code,
+                                                   int extra_code1) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = Component::State::component();
+
+  component.diff_error_category_ = error_category;
+  component.diff_error_code_ = error_code;
+  component.diff_extra_code1_ = extra_code1;
+
+  if (component.diff_error_code_ != 0) {
+    TransitionState(base::MakeUnique<StateDownloading>(&component));
+    return;
+  }
+
+  DCHECK_EQ(static_cast<int>(ErrorCategory::kErrorNone),
+            component.diff_error_category_);
+  DCHECK_EQ(0, component.diff_error_code_);
+  DCHECK_EQ(0, component.diff_extra_code1_);
+
+  DCHECK_EQ(static_cast<int>(ErrorCategory::kErrorNone),
+            component.error_category_);
+  DCHECK_EQ(0, component.error_code_);
+  DCHECK_EQ(0, component.extra_code1_);
+
+  TransitionState(base::MakeUnique<StateUpdated>(&component));
+}
+
+Component::StateUpdating::StateUpdating(Component* component)
+    : State(component, ComponentState::kUpdating),
+      main_task_runner_(base::ThreadTaskRunnerHandle::Get()) {}
+
+Component::StateUpdating::~StateUpdating() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateUpdating::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const auto& component = Component::State::component();
+  const auto& update_context = component.update_context_;
+
+  component.NotifyObservers(Events::COMPONENT_UPDATE_READY);
+
+  update_context.blocking_task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(&update_client::StartInstallOnBlockingTaskRunner,
+                 base::ThreadTaskRunnerHandle::Get(),
+                 update_context.blocking_task_runner,
+                 component.crx_component_.pk_hash, component.crx_path_,
+                 component.next_fp_, component.crx_component_.installer,
+                 update_context.config->CreateOutOfProcessPatcher(),
+                 base::Bind(&Component::StateUpdating::InstallComplete,
+                            base::Unretained(this))));
+}
+
+void Component::StateUpdating::InstallComplete(int error_category,
+                                               int error_code,
+                                               int extra_code1) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = Component::State::component();
+
+  component.error_category_ = error_category;
+  component.error_code_ = error_code;
+  component.extra_code1_ = extra_code1;
+
+  if (component.error_code_ != 0) {
+    TransitionState(base::MakeUnique<StateUpdateError>(&component));
+    return;
+  }
+
+  DCHECK_EQ(static_cast<int>(ErrorCategory::kErrorNone),
+            component.error_category_);
+  DCHECK_EQ(0, component.error_code_);
+  DCHECK_EQ(0, component.extra_code1_);
+
+  TransitionState(base::MakeUnique<StateUpdated>(&component));
+}
+
+Component::StateUpdated::StateUpdated(Component* component)
+    : State(component, ComponentState::kUpdated) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+Component::StateUpdated::~StateUpdated() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateUpdated::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  auto& component = State::component();
+  component.crx_component_.version = component.next_version_;
+  component.crx_component_.fingerprint = component.next_fp_;
+
+  TransitionState(nullptr);
+  component.NotifyObservers(Events::COMPONENT_UPDATED);
+}
+
+Component::StateUninstalled::StateUninstalled(Component* component)
+    : State(component, ComponentState::kUninstalled) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+Component::StateUninstalled::~StateUninstalled() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void Component::StateUninstalled::DoHandle() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  TransitionState(nullptr);
+}
+
+}  // namespace update_client