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

ios/web/public/web_client.h

Index: ios/web/public/web_client.h
diff --git a/ios/web/public/web_client.h b/ios/web/public/web_client.h
index feeac03cdfa5601d37d188fcf628829ace2f5778..0ade6caadb6bb77b25b269a35cd0121c4dfceadc 100644
--- a/ios/web/public/web_client.h
+++ b/ios/web/public/web_client.h
@@ -18,7 +18,6 @@
 
 namespace base {
 class RefCountedMemory;
-class SchedulerWorkerPoolParams;
 }
 
 class GURL;
@@ -125,12 +124,10 @@ class WebClient {
       bool overridable,
       const base::Callback<void(bool)>& callback);
 
-  // Provides parameters for initializing the global task scheduler. If
-  // |params_vector| is empty, default parameters are used.
-  virtual void GetTaskSchedulerInitializationParams(
-      std::vector<base::SchedulerWorkerPoolParams>* params_vector,
-      base::TaskScheduler::WorkerPoolIndexForTraitsCallback*
-          index_to_traits_callback) {}
+  // Provides parameters for initializing the global task scheduler. Default
+  // params are used if this returns nullptr.
+  virtual std::unique_ptr<base::TaskScheduler::InitParams>
+  GetTaskSchedulerInitParams();
 
   // Performs any necessary PostTask API redirection to the task scheduler.
   virtual void PerformExperimentalTaskSchedulerRedirections() {}