More specific typing in response handlers

src/objective-c/GRPCClient/GRPCCall.h

@@ -160,7 +160,7 @@ extern id const kGRPCTrailersKey;
  * Issued when a message is received from the server. The message is the raw data received from the
  * server, with decompression and without proto deserialization.
  */
-- (void)receivedRawMessage:(id)message;
+- (void)receivedRawMessage:(NSData *)message;
 
 /**
  * Issued when a call finished. If the call finished successfully, \a error is nil and \a

src/objective-c/ProtoRPC/ProtoRPC.h

@@ -34,7 +34,7 @@
 /**
  * Issued when a message is received from the server. The message is the deserialized proto object.
  */
-- (void)receivedProtoMessage:(id)message;
+- (void)receivedProtoMessage:(GPBMessage *)message;
 
 /**
  * Issued when a call finished. If the call finished successfully, \a error is nil and \a

src/objective-c/ProtoRPC/ProtoRPC.m

@@ -168,7 +168,7 @@
   if (_handler) {
     id<GRPCProtoResponseHandler> handler = _handler;
     NSError *error = nil;
-    id parsed = [_responseClass parseFromData:message error:&error];
+    GPBMessage *parsed = [_responseClass parseFromData:message error:&error];
     if (parsed) {
       if ([handler respondsToSelector:@selector(receivedProtoMessage:)]) {
         dispatch_async(handler.dispatchQueue, ^{

src/objective-c/tests/GRPCClientTests.m

@@ -120,7 +120,7 @@ static GRPCProtoMethod *kFullDuplexCallMethod;
   }
 }
 
-- (void)receivedProtoMessage:(id)message {
+- (void)receivedProtoMessage:(GPBMessage *)message {
   if (_messageCallback) {
     _messageCallback(message);
   }

src/objective-c/tests/InteropTests.m

@@ -108,7 +108,7 @@ BOOL isRemoteInteropTest(NSString *host) {
   }
 }
 
-- (void)receivedProtoMessage:(id)message {
+- (void)receivedProtoMessage:(GPBMessage *)message {
   if (_messageCallback) {
     _messageCallback(message);
   }