Add stream operators for URLPattern and URLPatternSet and unit test for URLPatternSet

extensions/common/url_pattern.cc

Index: extensions/common/url_pattern.cc
diff --git a/extensions/common/url_pattern.cc b/extensions/common/url_pattern.cc
index 020be3c40dfb4b64cab952257bc90cfddcc9271e..81176d2c69ceea96b35e9c0096cc31427f397f66 100644
--- a/extensions/common/url_pattern.cc
+++ b/extensions/common/url_pattern.cc
@@ -4,6 +4,8 @@
 
 #include "extensions/common/url_pattern.h"
 
+#include <ostream>
+
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
@@ -148,6 +150,10 @@ bool URLPattern::operator==(const URLPattern& other) const {
   return GetAsString() == other.GetAsString();
 }
 
+std::ostream& operator<<(std::ostream& out, const URLPattern& url_pattern) {
+  return out << '"' << url_pattern.GetAsString() << '"';
+}
+
 URLPattern::ParseResult URLPattern::Parse(const std::string& pattern) {
   spec_.clear();
   SetMatchAllURLs(false);