rawdata: update callers in delta utils

We update callers incrementally because this help bisecting failures. This was
useful during development, so we expect it might be useful again in the future.

mercurial/revlogutils/deltas.py

@@ -925,7 +925,7 b' class deltacomputer(object):'
             header = mdiff.replacediffheader(revlog.rawsize(base), len(t))
             delta = header + t
         else:
-            ptext = revlog.revision(base, _df=fh, raw=True)
+            ptext = revlog.rawdata(base, _df=fh)
             delta = mdiff.textdiff(ptext, t)
 
         return delta