autofill: switch autofill_regexes to RE2 library

components/autofill/core/browser/credit_card_field.cc

Index: components/autofill/core/browser/credit_card_field.cc
diff --git a/components/autofill/core/browser/credit_card_field.cc b/components/autofill/core/browser/credit_card_field.cc
index 3b24ec38c1851268949aaa7ce297cda4ded4c9d8..a7e4cae912350396bc574c313ab0993b2d5a6f76 100644
--- a/components/autofill/core/browser/credit_card_field.cc
+++ b/components/autofill/core/browser/credit_card_field.cc
@@ -40,7 +40,8 @@ bool FindConsecutiveStrings(const std::vector<base::string16>& regex_needles,
 
   for (size_t i = 0; i < haystack.size() - regex_needles.size() + 1; ++i) {
     for (size_t j = 0; j < regex_needles.size(); ++j) {
-      if (!MatchesPattern(haystack[i + j], regex_needles[j]))
+      if (!MatchesPattern(haystack[i + j],
+                          base::UTF16ToASCII(regex_needles[j])))
         break;
 
       if (j == regex_needles.size() - 1)
@@ -214,8 +215,7 @@ bool CreditCardField::LikelyCardMonthSelectField(AutofillScanner* scanner) {
     return false;
 
   // Filter out years.
-  const base::string16 kNumericalYearRe =
-      base::ASCIIToUTF16("[1-9][0-9][0-9][0-9]");
+  const char kNumericalYearRe[] = "[1-9][0-9][0-9][0-9]";
   for (const auto& value : field->option_values) {
     if (MatchesPattern(value, kNumericalYearRe))
       return false;
@@ -226,7 +226,7 @@ bool CreditCardField::LikelyCardMonthSelectField(AutofillScanner* scanner) {
   }
 
   // Look for numerical months.
-  const base::string16 kNumericalMonthRe = base::ASCIIToUTF16("12");
+  const char kNumericalMonthRe[] = "12";
   if (MatchesPattern(field->option_values.back(), kNumericalMonthRe) ||
       MatchesPattern(field->option_contents.back(), kNumericalMonthRe)) {
     return true;