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

extensions/common/url_pattern_set_unittest.cc

Index: extensions/common/url_pattern_set_unittest.cc
diff --git a/extensions/common/url_pattern_set_unittest.cc b/extensions/common/url_pattern_set_unittest.cc
index 267743a77435afc36e66b9978e1f371639c55cf4..1ad223ec53ac86db9deacef6d258330d7ceac03b 100644
--- a/extensions/common/url_pattern_set_unittest.cc
+++ b/extensions/common/url_pattern_set_unittest.cc
@@ -4,6 +4,8 @@
 
 #include "extensions/common/url_pattern_set.h"
 
+#include <sstream>
+
 #include "base/values.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
@@ -60,6 +62,34 @@ TEST(URLPatternSetTest, Two) {
   EXPECT_FALSE(set.MatchesURL(GURL("https://www.apple.com/monkey")));
 }
 
+TEST(URLPatternSetTest, StreamOperatorEmpty) {
+  URLPatternSet set;
+
+  std::ostringstream stream;
+  stream << set;
+  EXPECT_EQ("{ }", stream.str());
+}
+
+TEST(URLPatternSetTest, StreamOperatorOne) {
+  URLPatternSet set;
+  AddPattern(&set, "http://www.google.com/*");
+
+  std::ostringstream stream;
+  stream << set;
+  EXPECT_EQ("{ \"http://www.google.com/*\" }", stream.str());
+}
+
+TEST(URLPatternSetTest, StreamOperatorTwo) {
+  URLPatternSet set;
+  AddPattern(&set, "http://www.google.com/*");
+  AddPattern(&set, "http://www.yahoo.com/*");
+
+  std::ostringstream stream;
+  stream << set;
+  EXPECT_EQ("{ \"http://www.google.com/*\", \"http://www.yahoo.com/*\" }",
+            stream.str());
+}
+
 TEST(URLPatternSetTest, OverlapsWith) {
   URLPatternSet set1;
   AddPattern(&set1, "http://www.google.com/f*");