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 cdea63cb5c83c1ab3bca8008a6fa2fe0c44b7a73..3dfeeec505f1cc5b0a149d0d2bc883374ccf6b42 100644
--- a/components/autofill/core/common/autofill_regexes.cc
+++ b/components/autofill/core/common/autofill_regexes.cc
@@ -8,8 +8,7 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/singleton.h"
-#include "base/strings/string16.h"
-#include "third_party/icu/source/i18n/unicode/regex.h"
+#include "third_party/re2/re2/re2.h"
 
 namespace {
 
@@ -19,7 +18,7 @@ class AutofillRegexes {
   static AutofillRegexes* GetInstance();
 
   // Returns the compiled regex matcher corresponding to |pattern|.
-  icu::RegexMatcher* GetMatcher(const base::string16& pattern);
+  re2::RE2* GetMatcher(const std::string& pattern);
 
  private:
   AutofillRegexes();
@@ -27,8 +26,7 @@ class AutofillRegexes {
   friend struct base::DefaultSingletonTraits<AutofillRegexes>;
 
   // Maps patterns to their corresponding regex matchers.
-  base::ScopedPtrHashMap<base::string16, scoped_ptr<icu::RegexMatcher>>
-      matchers_;
+  base::ScopedPtrHashMap<std::string, scoped_ptr<re2::RE2>> matchers_;
 
   DISALLOW_COPY_AND_ASSIGN(AutofillRegexes);
 };
@@ -44,16 +42,11 @@ AutofillRegexes::AutofillRegexes() {
 AutofillRegexes::~AutofillRegexes() {
 }
 
-icu::RegexMatcher* AutofillRegexes::GetMatcher(const base::string16& pattern) {
+re2::RE2* AutofillRegexes::GetMatcher(const std::string& pattern) {
   auto it = matchers_.find(pattern);
   if (it == matchers_.end()) {
-    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));
-
+    scoped_ptr<re2::RE2> matcher(new re2::RE2(pattern));
+    DCHECK(matcher->ok());
     auto result = matchers_.add(pattern, matcher.Pass());
     DCHECK(result.second);
     it = result.first;
@@ -65,17 +58,9 @@ icu::RegexMatcher* AutofillRegexes::GetMatcher(const base::string16& pattern) {
 
 namespace autofill {
 
-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;
+bool MatchesPattern(const std::string& input, const std::string& pattern) {
+  re2::RE2* matcher = AutofillRegexes::GetInstance()->GetMatcher(pattern);

[Ilya Sherman, 2015/11/19 02:09:00]

Please add a TODO to verify whether it's still worthwhile to cache the regex
objects.  For example,

""" 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/XXXXXX"

[tfarina, 2015/11/20 19:03:37]

Done.

+  return re2::RE2::FullMatch(input, *matcher);

[Ilya Sherman, 2015/11/19 02:09:00]

Do the tests pass with this change?  I would have expected PartialMatch rather
than FullMatch.

[tfarina, 2015/11/20 19:03:37]

Now they do. Sorry for not getting to test this locally before. Now I did run
them properly and they all passed!

 }
 
 }  // namespace autofill