Provide a mechanism to the decl. WebRequest API to match URLs without the query against a RegEx

extensions/common/matcher/regex_set_matcher.cc

Index: extensions/common/matcher/regex_set_matcher.cc
diff --git a/extensions/common/matcher/regex_set_matcher.cc b/extensions/common/matcher/regex_set_matcher.cc
index c402f2e00b920b36e796b9bf0bbdfbc95a7b3d29..3052a637dbe7379fa9c225b57807b7b70210390f 100644
--- a/extensions/common/matcher/regex_set_matcher.cc
+++ b/extensions/common/matcher/regex_set_matcher.cc
@@ -61,6 +61,10 @@ bool RegexSetMatcher::Match(const std::string& text,
   return old_number_of_matches != matches->size();
 }
 
+bool RegexSetMatcher::IsEmpty() const {
+  return regexes_.empty();
+}
+
 std::vector<RegexSetMatcher::RE2ID> RegexSetMatcher::FindSubstringMatches(
     const std::string& text) const {
   std::set<int> atoms_set;