Use TaskScheduler::InitParams to initialize TaskScheduler in web_main_loop.mm.

ios/chrome/browser/web/chrome_web_client.mm

Index: ios/chrome/browser/web/chrome_web_client.mm
diff --git a/ios/chrome/browser/web/chrome_web_client.mm b/ios/chrome/browser/web/chrome_web_client.mm
index 25739254c3830d4a7482c3f1450728d6f1338c3c..2fe4de957e7d9dec9f1b2594b6594dfeb0a74852 100644
--- a/ios/chrome/browser/web/chrome_web_client.mm
+++ b/ios/chrome/browser/web/chrome_web_client.mm
@@ -171,17 +171,9 @@ void ChromeWebClient::AllowCertificateError(
                                      overridable, callback);
 }
 
-void ChromeWebClient::GetTaskSchedulerInitializationParams(
-    std::vector<base::SchedulerWorkerPoolParams>* params_vector,
-    base::TaskScheduler::WorkerPoolIndexForTraitsCallback*
-        index_to_traits_callback) {
-  DCHECK(params_vector);
-  DCHECK(index_to_traits_callback);
-  // If this call fails, web will fall back to the default params.
-  *params_vector =
-      task_scheduler_util::GetBrowserWorkerPoolParamsFromVariations();
-  *index_to_traits_callback =
-      base::Bind(&task_scheduler_util::BrowserWorkerPoolIndexForTraits);
+std::unique_ptr<base::TaskScheduler::InitParams>
+ChromeWebClient::GetTaskSchedulerInitParams() {
+  return task_scheduler_util::GetBrowserTaskSchedulerInitParamsFromVariations();
 }
 
 void ChromeWebClient::PerformExperimentalTaskSchedulerRedirections() {