[PM] Workaround for duplicate service worker controllees notifications

With this CL, the ServiceWorkerContextAdapter drops duplicate
OnControlleeAdded or OnControlleeRemoved notifications from the
ServiceWorkerContextObserver interface.

Bug: 993029, 1015692
Change-Id: I482a7d9db93cf6f8abd6475f7b0256f0f53857cf
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2354528Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#799272}

components/performance_manager/service_worker_context_adapter.cc

@@ -267,6 +267,43 @@ void ServiceWorkerContextAdapter::OnVersionStoppedRunning(int64_t version_id) {
     observer.OnVersionStoppedRunning(version_id);
 }
 
+void ServiceWorkerContextAdapter::OnControlleeAdded(
+    int64_t version_id,
+    const std::string& client_uuid,
+    const content::ServiceWorkerClientInfo& client_info) {
+  // If |client_uuid| is already marked as a client of |version_id|, the
+  // notification is dropped.
+  bool inserted =
+      service_worker_clients_[version_id].insert(client_uuid).second;
+  if (!inserted)
+    return;
+
+  for (auto& observer : observer_list_)
+    observer.OnControlleeAdded(version_id, client_uuid, client_info);
+}
+
+void ServiceWorkerContextAdapter::OnControlleeRemoved(
+    int64_t version_id,
+    const std::string& client_uuid) {
+  // If |client_uuid| is not already marked as a client of |version_id|, the
+  // notification is dropped.
+  auto it = service_worker_clients_.find(version_id);
+  if (it == service_worker_clients_.end())
+    return;
+
+  size_t removed = it->second.erase(client_uuid);
+  if (!removed)
+    return;
+
+  // If a service worker no longer has any clients, it is removed entirely from
+  // |service_worker_clients_|.
+  if (it->second.empty())
+    service_worker_clients_.erase(it);
+
+  for (auto& observer : observer_list_)
+    observer.OnControlleeRemoved(version_id, client_uuid);
+}
+
 void ServiceWorkerContextAdapter::OnNoControllees(int64_t version_id,
                                                   const GURL& scope) {
   for (auto& observer : observer_list_)

components/performance_manager/service_worker_context_adapter.h

@@ -100,6 +100,12 @@ class ServiceWorkerContextAdapter
       int64_t version_id,
       const content::ServiceWorkerRunningInfo& running_info) override;
   void OnVersionStoppedRunning(int64_t version_id) override;
+  void OnControlleeAdded(
+      int64_t version_id,
+      const std::string& client_uuid,
+      const content::ServiceWorkerClientInfo& client_info) override;
+  void OnControlleeRemoved(int64_t version_id,
+                           const std::string& client_uuid) override;
   void OnNoControllees(int64_t version_id, const GURL& scope) override;
   void OnReportConsoleMessage(int64_t version_id,
                               const GURL& scope,
@@ -124,6 +130,15 @@ class ServiceWorkerContextAdapter
   base::flat_map<int64_t /*version_id*/, std::unique_ptr<RunningServiceWorker>>
       running_service_workers_;
 
+  // Tracks the OnControlleeAdded and OnControlleeRemoved notification for each
+  // service worker, with the goal of cleaning up duplicate notifications for
+  // observers of this class.
+  // TODO(1015692): Fix the underlying code in content/browser/service_worker so
+  //                that duplicate notifications are no longer sent.
+  base::flat_map<int64_t /*version_id*/,
+                 base::flat_set<std::string /*client_uuid*/>>
+      service_worker_clients_;
+
 #if DCHECK_IS_ON()
   // Keeps track of service worker whose render process exited early.
   base::flat_set<int64_t> stopped_service_workers_;