[hvar] Rename advance function for clarity

src/hb-ot-hmtx-table.hh

@@ -295,9 +295,9 @@ struct hmtxvmtx
 	return advance;
 
       if (var_table.get_length ())
-	return advance + roundf (var_table->get_advance_var (glyph,
-							     font->coords, font->num_coords,
-							     store_cache)); // TODO Optimize?!
+	return advance + roundf (var_table->get_advance_delta_unscaled (glyph,
+									font->coords, font->num_coords,
+									store_cache)); // TODO Optimize?!
 
       return _glyf_get_advance_with_var_unscaled (font, glyph, T::tableTag == HB_OT_TAG_vmtx);
 #else

src/hb-ot-var-hvar-table.hh

@@ -319,9 +319,9 @@ struct HVARVVAR
 						hvar_plan.index_map_plans.as_array ()));
   }
 
-  float get_advance_var (hb_codepoint_t  glyph,
-			 const int *coords, unsigned int coord_count,
-			 VariationStore::cache_t *store_cache = nullptr) const
+  float get_advance_delta_unscaled (hb_codepoint_t  glyph,
+				    const int *coords, unsigned int coord_count,
+				    VariationStore::cache_t *store_cache = nullptr) const
   {
     uint32_t varidx = (this+advMap).map (glyph);
     return (this+varStore).get_delta (varidx,