[Extensions] Code cleanup - const &s

chrome/common/extensions/manifest_handlers/automation.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/extensions/manifest_handlers/automation.h"
 
 #include <memory>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 288 matching lines @@
     as_object->matches.reset(info.matches.ToStringVector().release());
   }
   automation->as_object.reset(as_object);
   return automation;
 }
 
 AutomationInfo::AutomationInfo() : desktop(false), interact(false) {
 }
 
 AutomationInfo::AutomationInfo(bool desktop,
-                               const URLPatternSet matches,
+                               const URLPatternSet& matches,
                                bool interact)
-    : desktop(desktop), matches(matches), interact(interact) {
-}
+    : desktop(desktop), matches(matches), interact(interact) {}
 
 AutomationInfo::~AutomationInfo() {
 }
 
 }  // namespace extensions