protozero: DCHECK against zero field ids

Zero field ids aren't valid protobuf, so DCHECK that we never try to
create messages with such fields. Note that we don't add DCHECKs to
primitive field writers to avoid adding too much overhead in debug
builds.

Bug: 298923683
Change-Id: If9f134ec41e664a8548eaaf6c142081714b1fac1

src/protozero/message.cc

@@ -71,6 +71,7 @@ void Message::AppendString(uint32_t field_id, const char* str) {
 }
 
 void Message::AppendBytes(uint32_t field_id, const void* src, size_t size) {
+  PERFETTO_DCHECK(field_id);
   if (nested_message_)
     EndNestedMessage();
 
@@ -90,6 +91,7 @@ void Message::AppendBytes(uint32_t field_id, const void* src, size_t size) {
 size_t Message::AppendScatteredBytes(uint32_t field_id,
                                      ContiguousMemoryRange* ranges,
                                      size_t num_ranges) {
+  PERFETTO_DCHECK(field_id);
   if (nested_message_)
     EndNestedMessage();
 
@@ -143,6 +145,7 @@ uint32_t Message::Finalize() {
 }
 
 Message* Message::BeginNestedMessageInternal(uint32_t field_id) {
+  PERFETTO_DCHECK(field_id);
   if (nested_message_)
     EndNestedMessage();