Fix compile warning.

third_party/sfntly/src/subsetter/subsetter_impl.cc

 /*
  * Copyright 2011 Google Inc. All Rights Reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
@@ skipping 236 matching lines @@
           }
         }
       }
 
       glyph_id_processed->insert(*i);
     }
 
     glyph_id_remaining.clear();
     glyph_id_remaining = comp_glyph_id;
   }
+
+  return true;
 }
 
 CALLER_ATTACH Font* SubsetterImpl::Subset(const IntegerSet& glyph_ids) {
   // The tables are already checked in ResolveCompositeGlyphs().
   GlyphTablePtr glyph_table =
       down_cast<GlyphTable*>(font_->GetTable(Tag::glyf));
   LocaTablePtr loca_table = down_cast<LocaTable*>(font_->GetTable(Tag::loca));
 
   // Setup font builders we need.
   FontBuilderPtr font_builder;
@@ skipping 59 matching lines @@
       TableBuilderPtr dereference;
       dereference.Attach(
           font_builder->NewTableBuilder(i->first, i->second->ReadFontData()));
     }
   }
 
   return font_builder->Build();
 }
 
 }  // namespace sfntly