Event tracing for sync events

chrome/browser/sync/syncable/model_type.h

Index: chrome/browser/sync/syncable/model_type.h
diff --git a/chrome/browser/sync/syncable/model_type.h b/chrome/browser/sync/syncable/model_type.h
index bfd9879c7b20c50b9762c7e72830e916b6277fb2..3ae1586717440c57618caf2e21938e6565de6d12 100644
--- a/chrome/browser/sync/syncable/model_type.h
+++ b/chrome/browser/sync/syncable/model_type.h
@@ -121,6 +121,10 @@ int GetExtensionFieldNumberFromModelType(ModelType model_type);
 
 // TODO(sync): The functions below badly need some cleanup.
 
+// Returns a pointer to a string with application lifetime that represents

[akalin, 2011/11/17 03:27:21]

How hard would it be to just make ModelTypeToString return a const char*?  If
it's hard, have a TODO to do so.

[rlarocque, 2011/11/17 19:37:53]

Turns out it's not very hard at all.  

Correct me if I'm wrong, but I think it's safe to trust the compiler to verify
this change.  I've made the change, fixed the compile errors, and everything
seems to work fine.  

[akalin, 2011/11/17 22:18:59]

I think that's safe enough, although it's possible that this change would e.g.
reduce a 'string == const char*' comparison to a 'const char* == const char*'
comparison or something.  It may be worth doing 'git grep ModelTypeToString' and
quickly auditing the callsites.

[rlarocque, 2011/11/18 02:47:10]

Good point, I hadn't thought of that issue.  

The git-grep doesn't turn up anything suspicious, so I'm still feeling pretty
good about this change.  

+// the name of |model_type|.
+const char* ModelTypeToCharPtr(ModelType model_type);
+
 // Returns a string that represents the name of |model_type|.
 std::string ModelTypeToString(ModelType model_type);