[M115] Fix segmentation fault on ExternallyManagedAppManager

As written in https://crbug.com/1449075, ExternallyManagedAppManager has
a compatibility issue with kServiceWorkerRegistrationCache feature. This
CL fixes the "segmentation fault" on ExternallyManagedAppManager.

<How can this CL avoid segmentation fault>

This CL initializes current_registration_ field first, and call
CheckHasServiceWorker() afterwards so that we can ensure that
current_registration_ is not null.

(cherry picked from commit 5d67e82)

Bug: 1449075, 1446216
Change-Id: Id4026fa414d091f9d24725a474a93b59a0326142
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4567903
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Alan Cutter <alancutter@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1149554}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4570941
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Minoru Chikamune <chikamune@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Dominick Ng <dominickn@chromium.org>
Cr-Commit-Position: refs/branch-heads/5790@{#125}
Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}

chrome/browser/web_applications/externally_managed_app_manager.cc

@@ -247,7 +247,7 @@ ExternallyManagedAppManager::CreateInstallationTask(
 }
 
 std::unique_ptr<ExternallyManagedAppRegistrationTaskBase>
-ExternallyManagedAppManager::StartRegistration(GURL install_url) {
+ExternallyManagedAppManager::CreateRegistration(GURL install_url) {
   DCHECK(!IsShuttingDown());
   ExternallyManagedAppRegistrationTask::RegistrationCallback callback =
       base::BindOnce(&ExternallyManagedAppManager::OnRegistrationFinished,
@@ -411,7 +411,8 @@ bool ExternallyManagedAppManager::RunNextRegistration() {
 
   GURL url_to_check = std::move(pending_registrations_.front());
   pending_registrations_.pop_front();
-  current_registration_ = StartRegistration(std::move(url_to_check));
+  current_registration_ = CreateRegistration(std::move(url_to_check));
+  current_registration_->Start();
   return true;
 }
 

chrome/browser/web_applications/externally_managed_app_manager.h

@@ -187,7 +187,7 @@ class ExternallyManagedAppManager {
   CreateInstallationTask(ExternalInstallOptions install_options);
 
   virtual std::unique_ptr<ExternallyManagedAppRegistrationTaskBase>
-  StartRegistration(GURL launch_url);
+  CreateRegistration(GURL launch_url);
 
   virtual void OnRegistrationFinished(const GURL& launch_url,
                                       RegistrationResultCode result);

chrome/browser/web_applications/externally_managed_app_manager_impl_unittest.cc

@@ -211,7 +211,7 @@ class TestExternallyManagedAppManager : public ExternallyManagedAppManager {
         std::move(install_options));
   }
 
-  std::unique_ptr<ExternallyManagedAppRegistrationTaskBase> StartRegistration(
+  std::unique_ptr<ExternallyManagedAppRegistrationTaskBase> CreateRegistration(
       GURL install_url) override {
     ++registration_run_count_;
     last_registered_install_url_ = install_url;
@@ -373,6 +373,8 @@ class TestExternallyManagedAppManager : public ExternallyManagedAppManager {
         const TestExternallyManagedAppRegistrationTask&) = delete;
     ~TestExternallyManagedAppRegistrationTask() override = default;
 
+    void Start() override {}
+
    private:
     void OnProgress(const GURL& install_url) {
       if (externally_managed_app_manager_impl_->MaybePreemptRegistration())

chrome/browser/web_applications/externally_managed_app_registration_task.cc

@@ -35,7 +35,9 @@ ExternallyManagedAppRegistrationTask::ExternallyManagedAppRegistrationTask(
     : ExternallyManagedAppRegistrationTaskBase(std::move(install_url)),
       url_loader_(url_loader),
       web_contents_(web_contents),
-      callback_(std::move(callback)) {
+      callback_(std::move(callback)) {}
+
+void ExternallyManagedAppRegistrationTask::Start() {
   content::StoragePartition* storage_partition =
       web_contents_->GetBrowserContext()->GetStoragePartition(
           web_contents_->GetSiteInstance());

chrome/browser/web_applications/externally_managed_app_registration_task.h

@@ -29,6 +29,7 @@ class WebAppUrlLoader;
 class ExternallyManagedAppRegistrationTaskBase
     : public content::ServiceWorkerContextObserver {
  public:
+  virtual void Start() = 0;
   ~ExternallyManagedAppRegistrationTaskBase() override;
 
   const GURL& install_url() const { return install_url_; }
@@ -59,6 +60,8 @@ class ExternallyManagedAppRegistrationTask
   void OnRegistrationCompleted(const GURL& scope) override;
   void OnDestruct(content::ServiceWorkerContext* context) override;
 
+  void Start() override;
+
   static void SetTimeoutForTesting(int registration_timeout_in_seconds);
 
  private: