[CleanUp] Use base::STLSetDifference in place of std::set_difference

extensions/common/matcher/url_matcher.cc

Index: extensions/common/matcher/url_matcher.cc
diff --git a/extensions/common/matcher/url_matcher.cc b/extensions/common/matcher/url_matcher.cc
index be3057a26b5f06502e55f407ec1de9223ee971c2..5a1d876cc6b8fa38967d1053df1de06f6f0d2c39 100644
--- a/extensions/common/matcher/url_matcher.cc
+++ b/extensions/common/matcher/url_matcher.cc
@@ -752,19 +752,15 @@ void URLMatcher::UpdateSubstringSetMatcher(bool full_url_conditions) {
                           : registered_url_component_patterns_;
 
   // Add all patterns that are in new_patterns but not in registered_patterns.
-  std::vector<const StringPattern*> patterns_to_register;
-  std::set_difference(
-      new_patterns.begin(), new_patterns.end(),
-      registered_patterns.begin(), registered_patterns.end(),
-      std::back_inserter(patterns_to_register));
+  std::vector<const StringPattern*> patterns_to_register =
+      base::STLSetDifference<std::vector<const StringPattern*> >(
+          new_patterns, registered_patterns);
 
   // Remove all patterns that are in registered_patterns but not in
   // new_patterns.
-  std::vector<const StringPattern*> patterns_to_unregister;
-  std::set_difference(
-      registered_patterns.begin(), registered_patterns.end(),
-      new_patterns.begin(), new_patterns.end(),
-      std::back_inserter(patterns_to_unregister));
+  std::vector<const StringPattern*> patterns_to_unregister =
+      base::STLSetDifference<std::vector<const StringPattern*> >(
+           registered_patterns, new_patterns);
 
   // Update the SubstringSetMatcher.
   SubstringSetMatcher& url_matcher =