Revert of Move JoinString to the base namespace

base/strings/string_util_unittest.cc

Index: base/strings/string_util_unittest.cc
diff --git a/base/strings/string_util_unittest.cc b/base/strings/string_util_unittest.cc
index 5d5ba8befdd9a2258337aabef52ec4cd9b9de19d..1593f8189679a24a97398dd18302b8eb71a31e91 100644
--- a/base/strings/string_util_unittest.cc
+++ b/base/strings/string_util_unittest.cc
@@ -669,7 +669,26 @@
   EXPECT_EQ(15, HexDigitToInt('f'));
 }
 
+// Test for JoinString
 TEST(StringUtilTest, JoinString) {
+  std::vector<std::string> in;
+  EXPECT_EQ("", JoinString(in, ','));
+
+  in.push_back("a");
+  EXPECT_EQ("a", JoinString(in, ','));
+
+  in.push_back("b");
+  in.push_back("c");
+  EXPECT_EQ("a,b,c", JoinString(in, ','));
+
+  in.push_back(std::string());
+  EXPECT_EQ("a,b,c,", JoinString(in, ','));
+  in.push_back(" ");
+  EXPECT_EQ("a|b|c|| ", JoinString(in, '|'));
+}
+
+// Test for JoinString overloaded with std::string separator
+TEST(StringUtilTest, JoinStringWithString) {
   std::string separator(", ");
   std::vector<std::string> parts;
   EXPECT_EQ(std::string(), JoinString(parts, separator));
@@ -687,7 +706,8 @@
   EXPECT_EQ("a|b|c|| ", JoinString(parts, "|"));
 }
 
-TEST(StringUtilTest, JoinString16) {
+// Test for JoinString overloaded with string16 separator
+TEST(StringUtilTest, JoinStringWithString16) {
   string16 separator = ASCIIToUTF16(", ");
   std::vector<string16> parts;
   EXPECT_EQ(string16(), JoinString(parts, separator));