Replace base::str[n]casecmp with helper functions.

net/cookies/cookie_util.cc

Index: net/cookies/cookie_util.cc
diff --git a/net/cookies/cookie_util.cc b/net/cookies/cookie_util.cc
index 2723363e2fb4e5271e21a826ced85402b7d90524..b9c7e8d601f8ed2e3c4d8b3eb07c8e1d0c5ffdae 100644
--- a/net/cookies/cookie_util.cc
+++ b/net/cookies/cookie_util.cc
@@ -125,7 +125,8 @@ base::Time ParseCookieTime(const std::string& time_string) {
       if (!found_month) {
         for (int i = 0; i < kMonthsLen; ++i) {
           // Match prefix, so we could match January, etc
-          if (base::strncasecmp(token.c_str(), kMonths[i], 3) == 0) {
+          if (base::StartsWith(token, base::StringPiece(kMonths[i], 3),
+                               base::CompareCase::INSENSITIVE_ASCII)) {
             exploded.month = i + 1;
             found_month = true;
             break;