Revert of autofill: switch autofill_regexes to RE2 library

components/autofill/core/common/autofill_regexes.cc

Index: components/autofill/core/common/autofill_regexes.cc
diff --git a/components/autofill/core/common/autofill_regexes.cc b/components/autofill/core/common/autofill_regexes.cc
index 7f914b9315db44c6c0215ee1de48c668479ba2fb..cdea63cb5c83c1ab3bca8008a6fa2fe0c44b7a73 100644
--- a/components/autofill/core/common/autofill_regexes.cc
+++ b/components/autofill/core/common/autofill_regexes.cc
@@ -8,8 +8,8 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
-#include "base/strings/utf_string_conversions.h"
-#include "third_party/re2/re2/re2.h"
+#include "base/strings/string16.h"
+#include "third_party/icu/source/i18n/unicode/regex.h"
 
 namespace {
 
@@ -19,7 +19,7 @@
   static AutofillRegexes* GetInstance();
 
   // Returns the compiled regex matcher corresponding to |pattern|.
-  re2::RE2* GetMatcher(const std::string& pattern);
+  icu::RegexMatcher* GetMatcher(const base::string16& pattern);
 
  private:
   AutofillRegexes();
@@ -27,7 +27,8 @@
   friend struct base::DefaultSingletonTraits<AutofillRegexes>;
 
   // Maps patterns to their corresponding regex matchers.
-  base::ScopedPtrHashMap<std::string, scoped_ptr<re2::RE2>> matchers_;
+  base::ScopedPtrHashMap<base::string16, scoped_ptr<icu::RegexMatcher>>
+      matchers_;
 
   DISALLOW_COPY_AND_ASSIGN(AutofillRegexes);
 };
@@ -43,13 +44,16 @@
 AutofillRegexes::~AutofillRegexes() {
 }
 
-re2::RE2* AutofillRegexes::GetMatcher(const std::string& pattern) {
+icu::RegexMatcher* AutofillRegexes::GetMatcher(const base::string16& pattern) {
   auto it = matchers_.find(pattern);
   if (it == matchers_.end()) {
-    re2::RE2::Options options;
-    options.set_case_sensitive(false);
-    scoped_ptr<re2::RE2> matcher(new re2::RE2(pattern, options));
-    DCHECK(matcher->ok());
+    const icu::UnicodeString icu_pattern(pattern.data(), pattern.length());
+
+    UErrorCode status = U_ZERO_ERROR;
+    scoped_ptr<icu::RegexMatcher> matcher(
+        new icu::RegexMatcher(icu_pattern, UREGEX_CASE_INSENSITIVE, status));
+    DCHECK(U_SUCCESS(status));
+
     auto result = matchers_.add(pattern, matcher.Pass());
     DCHECK(result.second);
     it = result.first;
@@ -61,12 +65,17 @@
 
 namespace autofill {
 
-bool MatchesPattern(const base::string16& input, const std::string& pattern) {
-  // TODO(isherman): Run performance tests to determine whether caching regex
-  // matchers is still useful now that we've switched from ICU to RE2.
-  // http://crbug.com/470065
-  re2::RE2* matcher = AutofillRegexes::GetInstance()->GetMatcher(pattern);
-  return re2::RE2::PartialMatch(base::UTF16ToUTF8(input), *matcher);
+bool MatchesPattern(const base::string16& input,
+                    const base::string16& pattern) {
+  icu::RegexMatcher* matcher =
+      AutofillRegexes::GetInstance()->GetMatcher(pattern);
+  icu::UnicodeString icu_input(input.data(), input.length());
+  matcher->reset(icu_input);
+
+  UErrorCode status = U_ZERO_ERROR;
+  UBool match = matcher->find(0, status);
+  DCHECK(U_SUCCESS(status));
+  return match == TRUE;
 }
 
 }  // namespace autofill