[Background Fetch] Cleanup after large refactor.

Few more minor changes that didn't make it in cr/1297412.

Bug: 850512
Change-Id: I7a1070135aa4d10a238c8c12fd4a95ffeac34343
Reviewed-on: https://chromium-review.googlesource.com/c/1320130
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606026}

content/browser/background_fetch/background_fetch_context.cc

@@ -107,6 +107,8 @@ void BackgroundFetchContext::GetDeveloperIdsForServiceWorker(
     int64_t service_worker_registration_id,
     const url::Origin& origin,
     blink::mojom::BackgroundFetchService::GetDeveloperIdsCallback callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
   data_manager_->GetDeveloperIdsForServiceWorker(service_worker_registration_id,
                                                  origin, std::move(callback));
 }
@@ -203,6 +205,7 @@ void BackgroundFetchContext::DidGetPermission(
   std::move(fetch_callbacks_[registration_id])
       .Run(blink::mojom::BackgroundFetchError::PERMISSION_DENIED,
            base::nullopt);
+  fetch_callbacks_.erase(registration_id);
 }
 
 void BackgroundFetchContext::GetIconDisplaySize(
@@ -277,10 +280,8 @@ void BackgroundFetchContext::DidGetMatchingRequests(
     std::vector<BackgroundFetchSettledFetch> settled_fetches) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
-  // TODO(crbug.com/863016): Update to 0u once we've stopped sending an
-  // uncached response.
   if (error != blink::mojom::BackgroundFetchError::NONE)
-    DCHECK_EQ(settled_fetches.size(), 1u);
+    DCHECK(settled_fetches.empty());
 
   std::move(callback).Run(std::move(settled_fetches));
 }

content/browser/background_fetch/background_fetch_data_manager.cc

@@ -58,7 +58,7 @@ void BackgroundFetchDataManager::InitializeOnIOThread() {
   cache_manager_ =
       base::WrapRefCounted(cache_storage_context_->cache_manager());
 
-  // TODO(crbug.com/855199): Persist which registrations to cleanup on startup.
+  // Delete inactive registrations still in the DB.
   Cleanup();
 
   DCHECK(cache_manager_);
@@ -197,7 +197,7 @@ void BackgroundFetchDataManager::AddDatabaseTask(
     return;
 
   database_tasks_.push(std::move(task));
-  if (database_tasks_.size() == 1)
+  if (database_tasks_.size() == 1u)
     database_tasks_.front()->Start();
 }
 

content/browser/background_fetch/background_fetch_scheduler.cc

@@ -5,6 +5,7 @@
 #include "content/browser/background_fetch/background_fetch_scheduler.h"
 
 #include "base/guid.h"
+#include "base/stl_util.h"
 #include "content/browser/background_fetch/background_fetch_data_manager.h"
 #include "content/browser/background_fetch/background_fetch_delegate_proxy.h"
 #include "content/browser/background_fetch/background_fetch_job_controller.h"
@@ -39,21 +40,15 @@ BackgroundFetchScheduler::~BackgroundFetchScheduler() = default;
 void BackgroundFetchScheduler::ScheduleDownload() {
   DCHECK(!active_controller_);
 
-  if (job_controllers_.empty())
-    return;
-
-  while (controller_ids_.size() &&
-         !job_controllers_.count(controller_ids_.front())) {
-    // Remove aborted controller ids.
-    controller_ids_.pop_front();
-  }
-
   if (controller_ids_.empty())
     return;
 
+  DCHECK(!job_controllers_.empty());
+
   std::string controller_id = controller_ids_.front();
   controller_ids_.pop_front();
   active_controller_ = job_controllers_[controller_id].get();
+  DCHECK(active_controller_);
 
   data_manager_->PopNextRequest(
       active_controller_->registration_id(),
@@ -68,6 +63,8 @@ void BackgroundFetchScheduler::Abort(
   DCHECK_EQ(failure_reason,
             BackgroundFetchFailureReason::CANCELLED_BY_DEVELOPER);
 
+  base::Erase(controller_ids_, registration_id.unique_id());
+
   auto it = job_controllers_.find(registration_id.unique_id());
   if (it == job_controllers_.end()) {
     std::move(callback).Run(BackgroundFetchError::INVALID_ID);
@@ -296,6 +293,8 @@ void BackgroundFetchScheduler::AbortFetches(
   }
 
   for (auto* controller : to_abort) {
+    // Erase it from |controller_ids_| first to avoid rescheduling.
+    base::Erase(controller_ids_, controller->registration_id().unique_id());
     controller->Abort(BackgroundFetchFailureReason::SERVICE_WORKER_UNAVAILABLE,
                       base::DoNothing());
   }