Fixup codegen now that GRXWriter is a class

src/compiler/objective_c_generator.cc

@@ -186,9 +186,6 @@ string GetHeader(const ServiceDescriptor *service) {
     grpc::protobuf::io::StringOutputStream output_stream(&output);
     Printer printer(&output_stream, '$');
 
-    printer.Print("@protocol GRXWriteable;\n");
-    printer.Print("@protocol GRXWriter;\n\n");
-
     map<string, string> vars = {{"service_class", ServiceClassName(service)}};
 
     printer.Print(vars, "@protocol $service_class$ <NSObject>\n\n");

src/compiler/objective_c_plugin.cc

@@ -63,7 +63,9 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
       // Generate .pbrpc.h
 
       string imports = string("#import \"") + file_name + ".pbobjc.h\"\n\n"
-        "#import <ProtoRPC/ProtoService.h>\n";
+        "#import <ProtoRPC/ProtoService.h>\n"
+        "#import <RxLibrary/GRXWriteable.h>\n"
+        "#import <RxLibrary/GRXWriter.h>\n";
 
       // TODO(jcanizales): Instead forward-declare the input and output types
       // and import the files in the .pbrpc.m
@@ -89,7 +91,6 @@ class ObjectiveCGrpcGenerator : public grpc::protobuf::compiler::CodeGenerator {
 
       string imports = string("#import \"") + file_name + ".pbrpc.h\"\n\n"
         "#import <ProtoRPC/ProtoRPC.h>\n"
-        "#import <RxLibrary/GRXWriteable.h>\n"
         "#import <RxLibrary/GRXWriter+Immediate.h>\n";
 
       string definitions;