Remove support for custom NSURLProtocol.

ios/chrome/app/startup/network_stack_setup.h

Index: ios/chrome/app/startup/network_stack_setup.h
diff --git a/ios/chrome/app/startup/network_stack_setup.h b/ios/chrome/app/startup/network_stack_setup.h
index 8bdfbe0c7160f24686c0c3daaa570584a3fba121..013b9d8079d44248278067b587288b9fee668bc2 100644
--- a/ios/chrome/app/startup/network_stack_setup.h
+++ b/ios/chrome/app/startup/network_stack_setup.h
@@ -11,19 +11,13 @@
 
 namespace web {
 class RequestTrackerFactoryImpl;
-class WebHTTPProtocolHandlerDelegate;
 }  // namespace web
 
 @interface NetworkStackSetup : NSObject
 
 // Sets up the network stack: protocol handler and cache.
-// TODO(crbug.com/585700): Remove the first parameter.
-+ (void)setUpChromeNetworkStack:
-            (std::unique_ptr<web::RequestTrackerFactoryImpl>*)
-                requestTrackerFactory
-    httpProtocolHandlerDelegate:
-        (std::unique_ptr<web::WebHTTPProtocolHandlerDelegate>*)
-            httpProtocolHandlerDelegate;
+// TODO(crbug.com/585700): Remove the return value.
++ (std::unique_ptr<web::RequestTrackerFactoryImpl>)setUpChromeNetworkStack;
 
 @end