Merge pull request #15303 from grpc/revert-15262-revert-15258-revert-15193-service-init-protocol

Revert "Revert "Revert "Provide protocol for initializer of generated messages"""

src/compiler/objective_c_generator.cc

@@ -222,8 +222,7 @@ void PrintMethodImplementations(Printer* printer,
   map< ::grpc::string, ::grpc::string> vars = {
       {"service_class", ServiceClassName(service)}};
 
-  printer.Print(
-      vars, "@protocol $service_class$ <NSObject, GRPCProtoServiceInit>\n\n");
+  printer.Print(vars, "@protocol $service_class$ <NSObject>\n\n");
   for (int i = 0; i < service->method_count(); i++) {
     PrintMethodDeclarations(&printer, service->method(i));
   }

src/objective-c/ProtoRPC/ProtoService.h

@@ -22,12 +22,6 @@
 @protocol GRXWriteable;
 @class GRXWriter;
 
-@protocol GRPCProtoServiceInit
-
-- (instancetype)initWithHost:(NSString *)host;
-
-@end
-
 __attribute__((deprecated("Please use GRPCProtoService."))) @interface ProtoService
     : NSObject -
       (instancetype)initWithHost : (NSString *)host packageName