Only allow certain files in net to depend on icu.

Also split out functions that depend on icu from net_util.cc.

This is a first step in allowing net/ to be build without icu,
using platform functions instead, to get binary site down when
used as a library on mobile.

BUG=362608
R=mef@chromium.org

Review URL: https://codereview.chromium.org/235373003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263850 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 932 insertions, 850 deletions

diff --git a/net/DEPS b/net/DEPS
index dca2b5b..a0a6e5a 100644
--- a/net/DEPS
+++ b/net/DEPS
@@ -8,8 +8,68 @@ include_rules = [
   "+third_party/zlib",
   "+sdch/open-vcdiff",
   "+v8",
+
+  # Most of net should not depend on icu, to keep size down when built as a
+  # library.
+  "-base/i18n",
+  "-third_party/icu",
 ]
 
+specific_include_rules = {
+  # Within net, only used by file: requests.
+  "directory_lister(\.cc|_unittest\.cc)": [
+    "+base/i18n",
+  ],
+
+  # Within net, only used by file: requests.
+  "filename_util\.cc": [
+    "+base/i18n",
+  ],
+  
+  # Functions largely not used by the rest of net.
+  "net_util_icu\.cc": [
+    "+base/i18n",
+    "+third_party/icu",
+  ],
+  
+  # Uses icu for debug logging only.
+  "network_time_notifier\.cc": [
+    "+base/i18n",
+  ],
+
+  # Only use icu for string conversions.
+  "escape_unittest\.cc": [
+    "+base/i18n/icu_string_conversions.h",
+  ],
+  "http_auth_handler_basic\.cc": [
+    "+base/i18n/icu_string_conversions.h",
+  ],
+  "http_auth_handler_digest\.cc": [
+    "+base/i18n/icu_string_conversions.h",
+  ],
+  "proxy_script_fetcher_impl\.cc": [
+    "+base/i18n/icu_string_conversions.h",
+  ],
+  "x509_cert_types_mac\.cc": [
+    "+base/i18n/icu_string_conversions.h",
+  ],
+  "http_content_disposition\.cc": [
+    "+base/i18n/icu_string_conversions.h",
+    "+third_party/icu",
+  ],
+  "websocket_channel\.h": [
+    "+base/i18n",
+  ],
+
+  "ftp_util\.cc": [
+    "+base/i18n",
+    "+third_party/icu",
+  ],
+  "ftp_directory_listing_parser\.cc": [
+    "+base/i18n",
+  ],
+}
+
 skip_child_includes = [
   "third_party",
   "tools/flip_server",
diff --git a/net/base/net_util.cc b/net/base/net_util.cc
index 106486d..d0355df 100644
--- a/net/base/net_util.cc
+++ b/net/base/net_util.cc
@@ -8,7 +8,6 @@
 
 #include <algorithm>
 #include <iterator>
-#include <map>
 #include <set>
 
 #include "build/build_config.h"
@@ -31,26 +30,16 @@
 #endif  // defined(OS_POSIX)
 
 #include "base/basictypes.h"
-#include "base/i18n/time_formatting.h"
 #include "base/json/string_escape.h"
 #include "base/lazy_instance.h"
 #include "base/logging.h"
-#include "base/memory/singleton.h"
-#include "base/message_loop/message_loop.h"
-#include "base/metrics/histogram.h"
-#include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
-#include "base/strings/string_tokenizer.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
-#include "base/strings/sys_string_conversions.h"
-#include "base/strings/utf_offset_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/synchronization/lock.h"
 #include "base/sys_byteorder.h"
-#include "base/time/time.h"
 #include "base/values.h"
 #include "grit/net_resources.h"
 #include "url/gurl.h"
@@ -58,17 +47,9 @@
 #include "url/url_canon_ip.h"
 #include "url/url_parse.h"
 #include "net/base/dns_util.h"
-#include "net/base/escape.h"
 #include "net/base/net_module.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
 #include "net/http/http_content_disposition.h"
-#include "third_party/icu/source/common/unicode/uidna.h"
-#include "third_party/icu/source/common/unicode/uniset.h"
-#include "third_party/icu/source/common/unicode/uscript.h"
-#include "third_party/icu/source/common/unicode/uset.h"
-#include "third_party/icu/source/i18n/unicode/datefmt.h"
-#include "third_party/icu/source/i18n/unicode/regex.h"
-#include "third_party/icu/source/i18n/unicode/ulocdata.h"
 
 #if defined(OS_ANDROID)
 #include "net/android/network_library.h"
@@ -77,14 +58,10 @@
 #include "net/base/winsock_init.h"
 #endif
 
-using base::Time;
-
 namespace net {
 
 namespace {
 
-typedef std::vector<size_t> Offsets;
-
 // The general list of blocked ports. Will be blocked unless a specific
 // protocol overrides it. (Ex: ftp can use ports 20 and 21)
 static const int kRestrictedPorts[] = {
@@ -163,595 +140,6 @@ static const int kAllowedFtpPorts[] = {
   22,   // ssh
 };
 
-// Does some simple normalization of scripts so we can allow certain scripts
-// to exist together.
-// TODO(brettw) bug 880223: we should allow some other languages to be
-// oombined such as Chinese and Latin. We will probably need a more
-// complicated system of language pairs to have more fine-grained control.
-UScriptCode NormalizeScript(UScriptCode code) {
-  switch (code) {
-    case USCRIPT_KATAKANA:
-    case USCRIPT_HIRAGANA:
-    case USCRIPT_KATAKANA_OR_HIRAGANA:
-    case USCRIPT_HANGUL:  // This one is arguable.
-      return USCRIPT_HAN;
-    default:
-      return code;
-  }
-}
-
-bool IsIDNComponentInSingleScript(const base::char16* str, int str_len) {
-  UScriptCode first_script = USCRIPT_INVALID_CODE;
-  bool is_first = true;
-
-  int i = 0;
-  while (i < str_len) {
-    unsigned code_point;
-    U16_NEXT(str, i, str_len, code_point);
-
-    UErrorCode err = U_ZERO_ERROR;
-    UScriptCode cur_script = uscript_getScript(code_point, &err);
-    if (err != U_ZERO_ERROR)
-      return false;  // Report mixed on error.
-    cur_script = NormalizeScript(cur_script);
-
-    // TODO(brettw) We may have to check for USCRIPT_INHERENT as well.
-    if (is_first && cur_script != USCRIPT_COMMON) {
-      first_script = cur_script;
-      is_first = false;
-    } else {
-      if (cur_script != USCRIPT_COMMON && cur_script != first_script)
-        return false;
-    }
-  }
-  return true;
-}
-
-// Check if the script of a language can be 'safely' mixed with
-// Latin letters in the ASCII range.
-bool IsCompatibleWithASCIILetters(const std::string& lang) {
-  // For now, just list Chinese, Japanese and Korean (positive list).
-  // An alternative is negative-listing (languages using Greek and
-  // Cyrillic letters), but it can be more dangerous.
-  return !lang.substr(0, 2).compare("zh") ||
-         !lang.substr(0, 2).compare("ja") ||
-         !lang.substr(0, 2).compare("ko");
-}
-
-typedef std::map<std::string, icu::UnicodeSet*> LangToExemplarSetMap;
-
-class LangToExemplarSet {
- public:
-  static LangToExemplarSet* GetInstance() {
-    return Singleton<LangToExemplarSet>::get();
-  }
-
- private:
-  LangToExemplarSetMap map;
-  LangToExemplarSet() { }
-  ~LangToExemplarSet() {
-    STLDeleteContainerPairSecondPointers(map.begin(), map.end());
-  }
-
-  friend class Singleton<LangToExemplarSet>;
-  friend struct DefaultSingletonTraits<LangToExemplarSet>;
-  friend bool GetExemplarSetForLang(const std::string&, icu::UnicodeSet**);
-  friend void SetExemplarSetForLang(const std::string&, icu::UnicodeSet*);
-
-  DISALLOW_COPY_AND_ASSIGN(LangToExemplarSet);
-};
-
-bool GetExemplarSetForLang(const std::string& lang,
-                           icu::UnicodeSet** lang_set) {
-  const LangToExemplarSetMap& map = LangToExemplarSet::GetInstance()->map;
-  LangToExemplarSetMap::const_iterator pos = map.find(lang);
-  if (pos != map.end()) {
-    *lang_set = pos->second;
-    return true;
-  }
-  return false;
-}
-
-void SetExemplarSetForLang(const std::string& lang,
-                           icu::UnicodeSet* lang_set) {
-  LangToExemplarSetMap& map = LangToExemplarSet::GetInstance()->map;
-  map.insert(std::make_pair(lang, lang_set));
-}
-
-static base::LazyInstance<base::Lock>::Leaky
-    g_lang_set_lock = LAZY_INSTANCE_INITIALIZER;
-
-// Returns true if all the characters in component_characters are used by
-// the language |lang|.
-bool IsComponentCoveredByLang(const icu::UnicodeSet& component_characters,
-                              const std::string& lang) {
-  CR_DEFINE_STATIC_LOCAL(
-      const icu::UnicodeSet, kASCIILetters, ('a', 'z'));
-  icu::UnicodeSet* lang_set = NULL;
-  // We're called from both the UI thread and the history thread.
-  {
-    base::AutoLock lock(g_lang_set_lock.Get());
-    if (!GetExemplarSetForLang(lang, &lang_set)) {
-      UErrorCode status = U_ZERO_ERROR;
-      ULocaleData* uld = ulocdata_open(lang.c_str(), &status);
-      // TODO(jungshik) Turn this check on when the ICU data file is
-      // rebuilt with the minimal subset of locale data for languages
-      // to which Chrome is not localized but which we offer in the list
-      // of languages selectable for Accept-Languages. With the rebuilt ICU
-      // data, ulocdata_open never should fall back to the default locale.
-      // (issue 2078)
-      // DCHECK(U_SUCCESS(status) && status != U_USING_DEFAULT_WARNING);
-      if (U_SUCCESS(status) && status != U_USING_DEFAULT_WARNING) {
-        lang_set = reinterpret_cast<icu::UnicodeSet *>(
-            ulocdata_getExemplarSet(uld, NULL, 0,
-                                    ULOCDATA_ES_STANDARD, &status));
-        // If |lang| is compatible with ASCII Latin letters, add them.
-        if (IsCompatibleWithASCIILetters(lang))
-          lang_set->addAll(kASCIILetters);
-      } else {
-        lang_set = new icu::UnicodeSet(1, 0);
-      }
-      lang_set->freeze();
-      SetExemplarSetForLang(lang, lang_set);
-      ulocdata_close(uld);
-    }
-  }
-  return !lang_set->isEmpty() && lang_set->containsAll(component_characters);
-}
-
-// Returns true if the given Unicode host component is safe to display to the
-// user.
-bool IsIDNComponentSafe(const base::char16* str,
-                        int str_len,
-                        const std::string& languages) {
-  // Most common cases (non-IDN) do not reach here so that we don't
-  // need a fast return path.
-  // TODO(jungshik) : Check if there's any character inappropriate
-  // (although allowed) for domain names.
-  // See http://www.unicode.org/reports/tr39/#IDN_Security_Profiles and
-  // http://www.unicode.org/reports/tr39/data/xidmodifications.txt
-  // For now, we borrow the list from Mozilla and tweaked it slightly.
-  // (e.g. Characters like U+00A0, U+3000, U+3002 are omitted because
-  //  they're gonna be canonicalized to U+0020 and full stop before
-  //  reaching here.)
-  // The original list is available at
-  // http://kb.mozillazine.org/Network.IDN.blacklist_chars and
-  // at http://mxr.mozilla.org/seamonkey/source/modules/libpref/src/init/all.js#703
-
-  UErrorCode status = U_ZERO_ERROR;
-#ifdef U_WCHAR_IS_UTF16
-  icu::UnicodeSet dangerous_characters(icu::UnicodeString(
-      L"[[\\ \u00ad\u00bc\u00bd\u01c3\u0337\u0338"
-      L"\u05c3\u05f4\u06d4\u0702\u115f\u1160][\u2000-\u200b]"
-      L"[\u2024\u2027\u2028\u2029\u2039\u203a\u2044\u205f]"
-      L"[\u2154-\u2156][\u2159-\u215b][\u215f\u2215\u23ae"
-      L"\u29f6\u29f8\u2afb\u2afd][\u2ff0-\u2ffb][\u3014"
-      L"\u3015\u3033\u3164\u321d\u321e\u33ae\u33af\u33c6\u33df\ufe14"
-      L"\ufe15\ufe3f\ufe5d\ufe5e\ufeff\uff0e\uff06\uff61\uffa0\ufff9]"
-      L"[\ufffa-\ufffd]]"), status);
-  DCHECK(U_SUCCESS(status));
-  icu::RegexMatcher dangerous_patterns(icu::UnicodeString(
-      // Lone katakana no, so, or n
-      L"[^\\p{Katakana}][\u30ce\u30f3\u30bd][^\\p{Katakana}]"
-      // Repeating Japanese accent characters
-      L"|[\u3099\u309a\u309b\u309c][\u3099\u309a\u309b\u309c]"),
-      0, status);
-#else
-  icu::UnicodeSet dangerous_characters(icu::UnicodeString(
-      "[[\\u0020\\u00ad\\u00bc\\u00bd\\u01c3\\u0337\\u0338"
-      "\\u05c3\\u05f4\\u06d4\\u0702\\u115f\\u1160][\\u2000-\\u200b]"
-      "[\\u2024\\u2027\\u2028\\u2029\\u2039\\u203a\\u2044\\u205f]"
-      "[\\u2154-\\u2156][\\u2159-\\u215b][\\u215f\\u2215\\u23ae"
-      "\\u29f6\\u29f8\\u2afb\\u2afd][\\u2ff0-\\u2ffb][\\u3014"
-      "\\u3015\\u3033\\u3164\\u321d\\u321e\\u33ae\\u33af\\u33c6\\u33df\\ufe14"
-      "\\ufe15\\ufe3f\\ufe5d\\ufe5e\\ufeff\\uff0e\\uff06\\uff61\\uffa0\\ufff9]"
-      "[\\ufffa-\\ufffd]]", -1, US_INV), status);
-  DCHECK(U_SUCCESS(status));
-  icu::RegexMatcher dangerous_patterns(icu::UnicodeString(
-      // Lone katakana no, so, or n
-      "[^\\p{Katakana}][\\u30ce\\u30f3\u30bd][^\\p{Katakana}]"
-      // Repeating Japanese accent characters
-      "|[\\u3099\\u309a\\u309b\\u309c][\\u3099\\u309a\\u309b\\u309c]"),
-      0, status);
-#endif
-  DCHECK(U_SUCCESS(status));
-  icu::UnicodeSet component_characters;
-  icu::UnicodeString component_string(str, str_len);
-  component_characters.addAll(component_string);
-  if (dangerous_characters.containsSome(component_characters))
-    return false;
-
-  DCHECK(U_SUCCESS(status));
-  dangerous_patterns.reset(component_string);
-  if (dangerous_patterns.find())
-    return false;
-
-  // If the language list is empty, the result is completely determined
-  // by whether a component is a single script or not. This will block
-  // even "safe" script mixing cases like <Chinese, Latin-ASCII> that are
-  // allowed with |languages| (while it blocks Chinese + Latin letters with
-  // an accent as should be the case), but we want to err on the safe side
-  // when |languages| is empty.
-  if (languages.empty())
-    return IsIDNComponentInSingleScript(str, str_len);
-
-  // |common_characters| is made up of  ASCII numbers, hyphen, plus and
-  // underscore that are used across scripts and allowed in domain names.
-  // (sync'd with characters allowed in url_canon_host with square
-  // brackets excluded.) See kHostCharLookup[] array in url_canon_host.cc.
-  icu::UnicodeSet common_characters(UNICODE_STRING_SIMPLE("[[0-9]\\-_+\\ ]"),
-                                    status);
-  DCHECK(U_SUCCESS(status));
-  // Subtract common characters because they're always allowed so that
-  // we just have to check if a language-specific set contains
-  // the remainder.
-  component_characters.removeAll(common_characters);
-
-  base::StringTokenizer t(languages, ",");
-  while (t.GetNext()) {
-    if (IsComponentCoveredByLang(component_characters, t.token()))
-      return true;
-  }
-  return false;
-}
-
-// A wrapper to use LazyInstance<>::Leaky with ICU's UIDNA, a C pointer to
-// a UTS46/IDNA 2008 handling object opened with uidna_openUTS46().
-//
-// We use UTS46 with BiDiCheck to migrate from IDNA 2003 to IDNA 2008 with
-// the backward compatibility in mind. What it does:
-//
-// 1. Use the up-to-date Unicode data.
-// 2. Define a case folding/mapping with the up-to-date Unicode data as
-//    in IDNA 2003.
-// 3. Use transitional mechanism for 4 deviation characters (sharp-s,
-//    final sigma, ZWJ and ZWNJ) for now.
-// 4. Continue to allow symbols and punctuations.
-// 5. Apply new BiDi check rules more permissive than the IDNA 2003 BiDI rules.
-// 6. Do not apply STD3 rules
-// 7. Do not allow unassigned code points.
-//
-// It also closely matches what IE 10 does except for the BiDi check (
-// http://goo.gl/3XBhqw ).
-// See http://http://unicode.org/reports/tr46/ and references therein
-// for more details.
-struct UIDNAWrapper {
-  UIDNAWrapper() {
-    UErrorCode err = U_ZERO_ERROR;
-    // TODO(jungshik): Change options as different parties (browsers,
-    // registrars, search engines) converge toward a consensus.
-    value = uidna_openUTS46(UIDNA_CHECK_BIDI, &err);
-    if (U_FAILURE(err))
-      value = NULL;
-  }
-
-  UIDNA* value;
-};
-
-static base::LazyInstance<UIDNAWrapper>::Leaky
-    g_uidna = LAZY_INSTANCE_INITIALIZER;
-
-// Converts one component of a host (between dots) to IDN if safe. The result
-// will be APPENDED to the given output string and will be the same as the input
-// if it is not IDN or the IDN is unsafe to display.  Returns whether any
-// conversion was performed.
-bool IDNToUnicodeOneComponent(const base::char16* comp,
-                              size_t comp_len,
-                              const std::string& languages,
-                              base::string16* out) {
-  DCHECK(out);
-  if (comp_len == 0)
-    return false;
-
-  // Only transform if the input can be an IDN component.
-  static const base::char16 kIdnPrefix[] = {'x', 'n', '-', '-'};
-  if ((comp_len > arraysize(kIdnPrefix)) &&
-      !memcmp(comp, kIdnPrefix, arraysize(kIdnPrefix) * sizeof(base::char16))) {
-    UIDNA* uidna = g_uidna.Get().value;
-    DCHECK(uidna != NULL);
-    size_t original_length = out->length();
-    int output_length = 64;
-    UIDNAInfo info = UIDNA_INFO_INITIALIZER;
-    UErrorCode status;
-    do {
-      out->resize(original_length + output_length);
-      status = U_ZERO_ERROR;
-      // This returns the actual length required. If this is more than 64
-      // code units, |status| will be U_BUFFER_OVERFLOW_ERROR and we'll try
-      // the conversion again, but with a sufficiently large buffer.
-      output_length = uidna_labelToUnicode(
-          uidna, comp, static_cast<int32_t>(comp_len), &(*out)[original_length],
-          output_length, &info, &status);
-    } while ((status == U_BUFFER_OVERFLOW_ERROR && info.errors == 0));
-
-    if (U_SUCCESS(status) && info.errors == 0) {
-      // Converted successfully. Ensure that the converted component
-      // can be safely displayed to the user.
-      out->resize(original_length + output_length);
-      if (IsIDNComponentSafe(out->data() + original_length, output_length,
-                             languages))
-        return true;
-    }
-
-    // Something went wrong. Revert to original string.
-    out->resize(original_length);
-  }
-
-  // We get here with no IDN or on error, in which case we just append the
-  // literal input.
-  out->append(comp, comp_len);
-  return false;
-}
-
-// Clamps the offsets in |offsets_for_adjustment| to the length of |str|.
-void LimitOffsets(const base::string16& str, Offsets* offsets_for_adjustment) {
-  if (offsets_for_adjustment) {
-    std::for_each(offsets_for_adjustment->begin(),
-                  offsets_for_adjustment->end(),
-                  base::LimitOffset<base::string16>(str.length()));
-  }
-}
-
-// TODO(brettw) bug 734373: check the scripts for each host component and
-// don't un-IDN-ize if there is more than one. Alternatively, only IDN for
-// scripts that the user has installed. For now, just put the entire
-// path through IDN. Maybe this feature can be implemented in ICU itself?
-//
-// We may want to skip this step in the case of file URLs to allow unicode
-// UNC hostnames regardless of encodings.
-base::string16 IDNToUnicodeWithOffsets(const std::string& host,
-                                       const std::string& languages,
-                                       Offsets* offsets_for_adjustment) {
-  // Convert the ASCII input to a base::string16 for ICU.
-  base::string16 input16;
-  input16.reserve(host.length());
-  input16.insert(input16.end(), host.begin(), host.end());
-
-  // Do each component of the host separately, since we enforce script matching
-  // on a per-component basis.
-  base::string16 out16;
-  {
-    base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
-    for (size_t component_start = 0, component_end;
-         component_start < input16.length();
-         component_start = component_end + 1) {
-      // Find the end of the component.
-      component_end = input16.find('.', component_start);
-      if (component_end == base::string16::npos)
-        component_end = input16.length();  // For getting the last component.
-      size_t component_length = component_end - component_start;
-      size_t new_component_start = out16.length();
-      bool converted_idn = false;
-      if (component_end > component_start) {
-        // Add the substring that we just found.
-        converted_idn = IDNToUnicodeOneComponent(
-            input16.data() + component_start, component_length, languages,
-            &out16);
-      }
-      size_t new_component_length = out16.length() - new_component_start;
-
-      if (converted_idn && offsets_for_adjustment) {
-        offset_adjuster.Add(base::OffsetAdjuster::Adjustment(component_start,
-            component_length, new_component_length));
-      }
-
-      // Need to add the dot we just found (if we found one).
-      if (component_end < input16.length())
-        out16.push_back('.');
-    }
-  }
-
-  LimitOffsets(out16, offsets_for_adjustment);
-  return out16;
-}
-
-// Called after transforming a component to set all affected elements in
-// |offsets_for_adjustment| to the correct new values.  |original_offsets|
-// represents the offsets before the transform; |original_component_begin| and
-// |original_component_end| represent the pre-transform boundaries of the
-// affected component.  |transformed_offsets| should be a vector created by
-// adjusting |original_offsets| to be relative to the beginning of the component
-// in question (via an OffsetAdjuster) and then transformed along with the
-// component.  Note that any elements in this vector which didn't originally
-// point into the component may contain arbitrary values and should be ignored.
-// |transformed_component_begin| and |transformed_component_end| are the
-// endpoints of the transformed component and are used in combination with the
-// two offset vectors to calculate the resulting absolute offsets, which are
-// stored in |offsets_for_adjustment|.
-void AdjustForComponentTransform(const Offsets& original_offsets,
-                                 size_t original_component_begin,
-                                 size_t original_component_end,
-                                 const Offsets& transformed_offsets,
-                                 size_t transformed_component_begin,
-                                 size_t transformed_component_end,
-                                 Offsets* offsets_for_adjustment) {
-  if (!offsets_for_adjustment)
-    return;  // Nothing to do.
-
-  for (size_t i = 0; i < original_offsets.size(); ++i) {
-    size_t original_offset = original_offsets[i];
-    if ((original_offset >= original_component_begin) &&
-        (original_offset < original_component_end)) {
-      // This offset originally pointed into the transformed component.
-      // Adjust the transformed relative offset by the new beginning point of
-      // the transformed component.
-      size_t transformed_offset = transformed_offsets[i];
-      (*offsets_for_adjustment)[i] =
-          (transformed_offset == base::string16::npos) ?
-              base::string16::npos :
-              (transformed_offset + transformed_component_begin);
-    } else if ((original_offset >= original_component_end) &&
-               (original_offset != std::string::npos)) {
-      // This offset pointed after the transformed component.  Adjust the
-      // original absolute offset by the difference between the new and old
-      // component lengths.
-      (*offsets_for_adjustment)[i] =
-          original_offset - original_component_end + transformed_component_end;
-    }
-  }
-}
-
-// If |component| is valid, its begin is incremented by |delta|.
-void AdjustComponent(int delta, url_parse::Component* component) {
-  if (!component->is_valid())
-    return;
-
-  DCHECK(delta >= 0 || component->begin >= -delta);
-  component->begin += delta;
-}
-
-// Adjusts all the components of |parsed| by |delta|, except for the scheme.
-void AdjustAllComponentsButScheme(int delta, url_parse::Parsed* parsed) {
-  AdjustComponent(delta, &(parsed->username));
-  AdjustComponent(delta, &(parsed->password));
-  AdjustComponent(delta, &(parsed->host));
-  AdjustComponent(delta, &(parsed->port));
-  AdjustComponent(delta, &(parsed->path));
-  AdjustComponent(delta, &(parsed->query));
-  AdjustComponent(delta, &(parsed->ref));
-}
-
-// Helper for FormatUrlWithOffsets().
-base::string16 FormatViewSourceUrl(const GURL& url,
-                                   const Offsets& original_offsets,
-                                   const std::string& languages,
-                                   FormatUrlTypes format_types,
-                                   UnescapeRule::Type unescape_rules,
-                                   url_parse::Parsed* new_parsed,
-                                   size_t* prefix_end,
-                                   Offsets* offsets_for_adjustment) {
-  DCHECK(new_parsed);
-  const char kViewSource[] = "view-source:";
-  const size_t kViewSourceLength = arraysize(kViewSource) - 1;
-
-  // Format the underlying URL and adjust offsets.
-  const std::string& url_str(url.possibly_invalid_spec());
-  Offsets offsets_into_underlying_url(original_offsets);
-  {
-    base::OffsetAdjuster adjuster(&offsets_into_underlying_url);
-    adjuster.Add(base::OffsetAdjuster::Adjustment(0, kViewSourceLength, 0));
-  }
-  base::string16 result(base::ASCIIToUTF16(kViewSource) +
-      FormatUrlWithOffsets(GURL(url_str.substr(kViewSourceLength)), languages,
-                           format_types, unescape_rules, new_parsed, prefix_end,
-                           &offsets_into_underlying_url));
-  AdjustForComponentTransform(original_offsets, kViewSourceLength,
-                              url_str.length(), offsets_into_underlying_url,
-                              kViewSourceLength, result.length(),
-                              offsets_for_adjustment);
-  LimitOffsets(result, offsets_for_adjustment);
-
-  // Adjust positions of the parsed components.
-  if (new_parsed->scheme.is_nonempty()) {
-    // Assume "view-source:real-scheme" as a scheme.
-    new_parsed->scheme.len += kViewSourceLength;
-  } else {
-    new_parsed->scheme.begin = 0;
-    new_parsed->scheme.len = kViewSourceLength - 1;
-  }
-  AdjustAllComponentsButScheme(kViewSourceLength, new_parsed);
-
-  if (prefix_end)
-    *prefix_end += kViewSourceLength;
-
-  return result;
-}
-
-class AppendComponentTransform {
- public:
-  AppendComponentTransform() {}
-  virtual ~AppendComponentTransform() {}
-
-  virtual base::string16 Execute(const std::string& component_text,
-                                 Offsets* offsets_into_component) const = 0;
-
-  // NOTE: No DISALLOW_COPY_AND_ASSIGN here, since gcc < 4.3.0 requires an
-  // accessible copy constructor in order to call AppendFormattedComponent()
-  // with an inline temporary (see http://gcc.gnu.org/bugs/#cxx%5Frvalbind ).
-};
-
-class HostComponentTransform : public AppendComponentTransform {
- public:
-  explicit HostComponentTransform(const std::string& languages)
-      : languages_(languages) {
-  }
-
- private:
-  virtual base::string16 Execute(
-      const std::string& component_text,
-      Offsets* offsets_into_component) const OVERRIDE {
-    return IDNToUnicodeWithOffsets(component_text, languages_,
-                                   offsets_into_component);
-  }
-
-  const std::string& languages_;
-};
-
-class NonHostComponentTransform : public AppendComponentTransform {
- public:
-  explicit NonHostComponentTransform(UnescapeRule::Type unescape_rules)
-      : unescape_rules_(unescape_rules) {
-  }
-
- private:
-  virtual base::string16 Execute(
-      const std::string& component_text,
-      Offsets* offsets_into_component) const OVERRIDE {
-    return (unescape_rules_ == UnescapeRule::NONE) ?
-        base::UTF8ToUTF16AndAdjustOffsets(component_text,
-                                          offsets_into_component) :
-        UnescapeAndDecodeUTF8URLComponentWithOffsets(component_text,
-            unescape_rules_, offsets_into_component);
-  }
-
-  const UnescapeRule::Type unescape_rules_;
-};
-
-// Transforms the portion of |spec| covered by |original_component| according to
-// |transform|.  Appends the result to |output|.  If |output_component| is
-// non-NULL, its start and length are set to the transformed component's new
-// start and length.  For each element in |original_offsets| which is at least
-// as large as original_component.begin, the corresponding element of
-// |offsets_for_adjustment| is transformed appropriately.
-void AppendFormattedComponent(const std::string& spec,
-                              const url_parse::Component& original_component,
-                              const Offsets& original_offsets,
-                              const AppendComponentTransform& transform,
-                              base::string16* output,
-                              url_parse::Component* output_component,
-                              Offsets* offsets_for_adjustment) {
-  DCHECK(output);
-  if (original_component.is_nonempty()) {
-    size_t original_component_begin =
-        static_cast<size_t>(original_component.begin);
-    size_t output_component_begin = output->length();
-    std::string component_str(spec, original_component_begin,
-                              static_cast<size_t>(original_component.len));
-
-    // Transform |component_str| and adjust the offsets accordingly.
-    Offsets offsets_into_component(original_offsets);
-    {
-      base::OffsetAdjuster adjuster(&offsets_into_component);
-      adjuster.Add(base::OffsetAdjuster::Adjustment(0, original_component_begin,
-                                                    0));
-    }
-    output->append(transform.Execute(component_str, &offsets_into_component));
-    AdjustForComponentTransform(original_offsets, original_component_begin,
-                                static_cast<size_t>(original_component.end()),
-                                offsets_into_component, output_component_begin,
-                                output->length(), offsets_for_adjustment);
-
-    // Set positions of the parsed component.
-    if (output_component) {
-      output_component->begin = static_cast<int>(output_component_begin);
-      output_component->len =
-          static_cast<int>(output->length() - output_component_begin);
-    }
-  } else if (output_component) {
-    output_component->reset();
-  }
-}
-
 bool IPNumberPrefixCheck(const IPAddressNumber& ip_number,
                          const unsigned char* ip_prefix,
                          size_t prefix_length_in_bits) {
@@ -776,13 +164,6 @@ bool IPNumberPrefixCheck(const IPAddressNumber& ip_number,
 
 }  // namespace
 
-const FormatUrlType kFormatUrlOmitNothing                     = 0;
-const FormatUrlType kFormatUrlOmitUsernamePassword            = 1 << 0;
-const FormatUrlType kFormatUrlOmitHTTP                        = 1 << 1;
-const FormatUrlType kFormatUrlOmitTrailingSlashOnBareHostname = 1 << 2;
-const FormatUrlType kFormatUrlOmitAll = kFormatUrlOmitUsernamePassword |
-    kFormatUrlOmitHTTP | kFormatUrlOmitTrailingSlashOnBareHostname;
-
 static base::LazyInstance<std::multiset<int> >::Leaky
     g_explicitly_allowed_ports = LAZY_INSTANCE_INITIALIZER;
 
@@ -821,11 +202,6 @@ std::string GetSpecificHeader(const std::string& headers,
   return ret;
 }
 
-base::string16 IDNToUnicode(const std::string& host,
-                            const std::string& languages) {
-  return IDNToUnicodeWithOffsets(host, languages, NULL);
-}
-
 std::string CanonicalizeHost(const std::string& host,
                              url_canon::CanonHostInfo* host_info) {
   // Try to canonicalize the host.
@@ -908,46 +284,6 @@ bool IsCanonicalizedHostCompliant(const std::string& host,
       (!desired_tld.empty() && IsHostCharAlphanumeric(desired_tld[0]));
 }
 
-std::string GetDirectoryListingEntry(const base::string16& name,
-                                     const std::string& raw_bytes,
-                                     bool is_dir,
-                                     int64 size,
-                                     Time modified) {
-  std::string result;
-  result.append("<script>addRow(");
-  base::EscapeJSONString(name, true, &result);
-  result.append(",");
-  if (raw_bytes.empty()) {
-    base::EscapeJSONString(EscapePath(base::UTF16ToUTF8(name)), true, &result);
-  } else {
-    base::EscapeJSONString(EscapePath(raw_bytes), true, &result);
-  }
-  if (is_dir) {
-    result.append(",1,");
-  } else {
-    result.append(",0,");
-  }
-
-  // Negative size means unknown or not applicable (e.g. directory).
-  base::string16 size_string;
-  if (size >= 0)
-    size_string = FormatBytesUnlocalized(size);
-  base::EscapeJSONString(size_string, true, &result);
-
-  result.append(",");
-
-  base::string16 modified_str;
-  // |modified| can be NULL in FTP listings.
-  if (!modified.is_null()) {
-    modified_str = base::TimeFormatShortDateAndTime(modified);
-  }
-  base::EscapeJSONString(modified_str, true, &result);
-
-  result.append(");</script>\n");
-
-  return result;
-}
-
 base::string16 StripWWW(const base::string16& text) {
   const base::string16 www(base::ASCIIToUTF16("www."));
   return StartsWith(text, www, true) ? text.substr(www.length()) : text;
@@ -958,7 +294,6 @@ base::string16 StripWWWFromHost(const GURL& url) {
   return StripWWW(base::ASCIIToUTF16(url.host()));
 }
 
-
 bool IsPortAllowedByDefault(int port) {
   int array_size = arraysize(kRestrictedPorts);
   for (int i = 0; i < array_size; i++) {
@@ -1299,191 +634,6 @@ std::string GetHostOrSpecFromURL(const GURL& url) {
   return url.has_host() ? TrimEndingDot(url.host()) : url.spec();
 }
 
-void AppendFormattedHost(const GURL& url,
-                         const std::string& languages,
-                         base::string16* output) {
-  Offsets offsets;
-  AppendFormattedComponent(url.possibly_invalid_spec(),
-      url.parsed_for_possibly_invalid_spec().host, offsets,
-      HostComponentTransform(languages), output, NULL, NULL);
-}
-
-base::string16 FormatUrlWithOffsets(
-    const GURL& url,
-    const std::string& languages,
-    FormatUrlTypes format_types,
-    UnescapeRule::Type unescape_rules,
-    url_parse::Parsed* new_parsed,
-    size_t* prefix_end,
-    Offsets* offsets_for_adjustment) {
-  url_parse::Parsed parsed_temp;
-  if (!new_parsed)
-    new_parsed = &parsed_temp;
-  else
-    *new_parsed = url_parse::Parsed();
-  Offsets original_offsets;
-  if (offsets_for_adjustment)
-    original_offsets = *offsets_for_adjustment;
-
-  // Special handling for view-source:.  Don't use content::kViewSourceScheme
-  // because this library shouldn't depend on chrome.
-  const char* const kViewSource = "view-source";
-  // Reject "view-source:view-source:..." to avoid deep recursion.
-  const char* const kViewSourceTwice = "view-source:view-source:";
-  if (url.SchemeIs(kViewSource) &&
-      !StartsWithASCII(url.possibly_invalid_spec(), kViewSourceTwice, false)) {
-    return FormatViewSourceUrl(url, original_offsets, languages, format_types,
-                               unescape_rules, new_parsed, prefix_end,
-                               offsets_for_adjustment);
-  }
-
-  // We handle both valid and invalid URLs (this will give us the spec
-  // regardless of validity).
-  const std::string& spec = url.possibly_invalid_spec();
-  const url_parse::Parsed& parsed = url.parsed_for_possibly_invalid_spec();
-
-  // Scheme & separators.  These are ASCII.
-  base::string16 url_string;
-  url_string.insert(url_string.end(), spec.begin(),
-      spec.begin() + parsed.CountCharactersBefore(url_parse::Parsed::USERNAME,
-                                                  true));
-  const char kHTTP[] = "http://";
-  const char kFTP[] = "ftp.";
-  // URLFixerUpper::FixupURL() treats "ftp.foo.com" as ftp://ftp.foo.com.  This
-  // means that if we trim "http://" off a URL whose host starts with "ftp." and
-  // the user inputs this into any field subject to fixup (which is basically
-  // all input fields), the meaning would be changed.  (In fact, often the
-  // formatted URL is directly pre-filled into an input field.)  For this reason
-  // we avoid stripping "http://" in this case.
-  bool omit_http = (format_types & kFormatUrlOmitHTTP) &&
-      EqualsASCII(url_string, kHTTP) &&
-      !StartsWithASCII(url.host(), kFTP, true);
-  new_parsed->scheme = parsed.scheme;
-
-  // Username & password.
-  if ((format_types & kFormatUrlOmitUsernamePassword) != 0) {
-    // Remove the username and password fields. We don't want to display those
-    // to the user since they can be used for attacks,
-    // e.g. "http://google.com:search@evil.ru/"
-    new_parsed->username.reset();
-    new_parsed->password.reset();
-    // Update the offsets based on removed username and/or password.
-    if (offsets_for_adjustment && !offsets_for_adjustment->empty() &&
-        (parsed.username.is_nonempty() || parsed.password.is_nonempty())) {
-      base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
-      if (parsed.username.is_nonempty() && parsed.password.is_nonempty()) {
-        // The seeming off-by-one and off-by-two in these first two lines are to
-        // account for the ':' after the username and '@' after the password.
-        offset_adjuster.Add(base::OffsetAdjuster::Adjustment(
-            static_cast<size_t>(parsed.username.begin),
-            static_cast<size_t>(parsed.username.len + parsed.password.len + 2),
-            0));
-      } else {
-        const url_parse::Component* nonempty_component =
-            parsed.username.is_nonempty() ? &parsed.username : &parsed.password;
-        // The seeming off-by-one in below is to account for the '@' after the
-        // username/password.
-        offset_adjuster.Add(base::OffsetAdjuster::Adjustment(
-            static_cast<size_t>(nonempty_component->begin),
-            static_cast<size_t>(nonempty_component->len + 1), 0));
-      }
-    }
-  } else {
-    AppendFormattedComponent(spec, parsed.username, original_offsets,
-        NonHostComponentTransform(unescape_rules), &url_string,
-        &new_parsed->username, offsets_for_adjustment);
-    if (parsed.password.is_valid())
-      url_string.push_back(':');
-    AppendFormattedComponent(spec, parsed.password, original_offsets,
-        NonHostComponentTransform(unescape_rules), &url_string,
-        &new_parsed->password, offsets_for_adjustment);
-    if (parsed.username.is_valid() || parsed.password.is_valid())
-      url_string.push_back('@');
-  }
-  if (prefix_end)
-    *prefix_end = static_cast<size_t>(url_string.length());
-
-  // Host.
-  AppendFormattedComponent(spec, parsed.host, original_offsets,
-      HostComponentTransform(languages), &url_string, &new_parsed->host,
-      offsets_for_adjustment);
-
-  // Port.
-  if (parsed.port.is_nonempty()) {
-    url_string.push_back(':');
-    new_parsed->port.begin = url_string.length();
-    url_string.insert(url_string.end(),
-                      spec.begin() + parsed.port.begin,
-                      spec.begin() + parsed.port.end());
-    new_parsed->port.len = url_string.length() - new_parsed->port.begin;
-  } else {
-    new_parsed->port.reset();
-  }
-
-  // Path & query.  Both get the same general unescape & convert treatment.
-  if (!(format_types & kFormatUrlOmitTrailingSlashOnBareHostname) ||
-      !CanStripTrailingSlash(url)) {
-    AppendFormattedComponent(spec, parsed.path, original_offsets,
-        NonHostComponentTransform(unescape_rules), &url_string,
-        &new_parsed->path, offsets_for_adjustment);
-  } else {
-    base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
-    offset_adjuster.Add(base::OffsetAdjuster::Adjustment(
-        url_string.length(), parsed.path.len, 0));
-  }
-  if (parsed.query.is_valid())
-    url_string.push_back('?');
-  AppendFormattedComponent(spec, parsed.query, original_offsets,
-      NonHostComponentTransform(unescape_rules), &url_string,
-      &new_parsed->query, offsets_for_adjustment);
-
-  // Ref.  This is valid, unescaped UTF-8, so we can just convert.
-  if (parsed.ref.is_valid())
-    url_string.push_back('#');
-  AppendFormattedComponent(spec, parsed.ref, original_offsets,
-      NonHostComponentTransform(UnescapeRule::NONE), &url_string,
-      &new_parsed->ref, offsets_for_adjustment);
-
-  // If we need to strip out http do it after the fact. This way we don't need
-  // to worry about how offset_for_adjustment is interpreted.
-  if (omit_http && StartsWith(url_string, base::ASCIIToUTF16(kHTTP), true)) {
-    const size_t kHTTPSize = arraysize(kHTTP) - 1;
-    url_string = url_string.substr(kHTTPSize);
-    if (offsets_for_adjustment && !offsets_for_adjustment->empty()) {
-      base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
-      offset_adjuster.Add(base::OffsetAdjuster::Adjustment(0, kHTTPSize, 0));
-    }
-    if (prefix_end)
-      *prefix_end -= kHTTPSize;
-
-    // Adjust new_parsed.
-    DCHECK(new_parsed->scheme.is_valid());
-    int delta = -(new_parsed->scheme.len + 3);  // +3 for ://.
-    new_parsed->scheme.reset();
-    AdjustAllComponentsButScheme(delta, new_parsed);
-  }
-
-  LimitOffsets(url_string, offsets_for_adjustment);
-  return url_string;
-}
-
-base::string16 FormatUrl(const GURL& url,
-                         const std::string& languages,
-                         FormatUrlTypes format_types,
-                         UnescapeRule::Type unescape_rules,
-                         url_parse::Parsed* new_parsed,
-                         size_t* prefix_end,
-                         size_t* offset_for_adjustment) {
-  Offsets offsets;
-  if (offset_for_adjustment)
-    offsets.push_back(*offset_for_adjustment);
-  base::string16 result = FormatUrlWithOffsets(url, languages, format_types,
-      unescape_rules, new_parsed, prefix_end, &offsets);
-  if (offset_for_adjustment)
-    *offset_for_adjustment = offsets[0];
-  return result;
-}
-
 bool CanStripTrailingSlash(const GURL& url) {
   // Omit the path only for standard, non-file URLs with nothing but "/" after
   // the hostname.
diff --git a/net/base/net_util_icu.cc b/net/base/net_util_icu.cc
new file mode 100644
index 0000000..2a4f6ff
--- /dev/null
+++ b/net/base/net_util_icu.cc
@@ -0,0 +1,866 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/base/net_util.h"
+
+#include <map>
+#include <vector>
+
+#include "base/i18n/time_formatting.h"
+#include "base/json/string_escape.h"
+#include "base/lazy_instance.h"
+#include "base/logging.h"
+#include "base/memory/singleton.h"
+#include "base/stl_util.h"
+#include "base/strings/string_tokenizer.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_offset_string_conversions.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
+#include "url/gurl.h"
+#include "third_party/icu/source/common/unicode/uidna.h"
+#include "third_party/icu/source/common/unicode/uniset.h"
+#include "third_party/icu/source/common/unicode/uscript.h"
+#include "third_party/icu/source/common/unicode/uset.h"
+#include "third_party/icu/source/i18n/unicode/datefmt.h"
+#include "third_party/icu/source/i18n/unicode/regex.h"
+#include "third_party/icu/source/i18n/unicode/ulocdata.h"
+
+using base::Time;
+
+namespace net {
+
+namespace {
+
+typedef std::vector<size_t> Offsets;
+
+// Does some simple normalization of scripts so we can allow certain scripts
+// to exist together.
+// TODO(brettw) bug 880223: we should allow some other languages to be
+// oombined such as Chinese and Latin. We will probably need a more
+// complicated system of language pairs to have more fine-grained control.
+UScriptCode NormalizeScript(UScriptCode code) {
+  switch (code) {
+    case USCRIPT_KATAKANA:
+    case USCRIPT_HIRAGANA:
+    case USCRIPT_KATAKANA_OR_HIRAGANA:
+    case USCRIPT_HANGUL:  // This one is arguable.
+      return USCRIPT_HAN;
+    default:
+      return code;
+  }
+}
+
+bool IsIDNComponentInSingleScript(const base::char16* str, int str_len) {
+  UScriptCode first_script = USCRIPT_INVALID_CODE;
+  bool is_first = true;
+
+  int i = 0;
+  while (i < str_len) {
+    unsigned code_point;
+    U16_NEXT(str, i, str_len, code_point);
+
+    UErrorCode err = U_ZERO_ERROR;
+    UScriptCode cur_script = uscript_getScript(code_point, &err);
+    if (err != U_ZERO_ERROR)
+      return false;  // Report mixed on error.
+    cur_script = NormalizeScript(cur_script);
+
+    // TODO(brettw) We may have to check for USCRIPT_INHERENT as well.
+    if (is_first && cur_script != USCRIPT_COMMON) {
+      first_script = cur_script;
+      is_first = false;
+    } else {
+      if (cur_script != USCRIPT_COMMON && cur_script != first_script)
+        return false;
+    }
+  }
+  return true;
+}
+
+// Check if the script of a language can be 'safely' mixed with
+// Latin letters in the ASCII range.
+bool IsCompatibleWithASCIILetters(const std::string& lang) {
+  // For now, just list Chinese, Japanese and Korean (positive list).
+  // An alternative is negative-listing (languages using Greek and
+  // Cyrillic letters), but it can be more dangerous.
+  return !lang.substr(0, 2).compare("zh") ||
+         !lang.substr(0, 2).compare("ja") ||
+         !lang.substr(0, 2).compare("ko");
+}
+
+typedef std::map<std::string, icu::UnicodeSet*> LangToExemplarSetMap;
+
+class LangToExemplarSet {
+ public:
+  static LangToExemplarSet* GetInstance() {
+    return Singleton<LangToExemplarSet>::get();
+  }
+
+ private:
+  LangToExemplarSetMap map;
+  LangToExemplarSet() { }
+  ~LangToExemplarSet() {
+    STLDeleteContainerPairSecondPointers(map.begin(), map.end());
+  }
+
+  friend class Singleton<LangToExemplarSet>;
+  friend struct DefaultSingletonTraits<LangToExemplarSet>;
+  friend bool GetExemplarSetForLang(const std::string&, icu::UnicodeSet**);
+  friend void SetExemplarSetForLang(const std::string&, icu::UnicodeSet*);
+
+  DISALLOW_COPY_AND_ASSIGN(LangToExemplarSet);
+};
+
+bool GetExemplarSetForLang(const std::string& lang,
+                           icu::UnicodeSet** lang_set) {
+  const LangToExemplarSetMap& map = LangToExemplarSet::GetInstance()->map;
+  LangToExemplarSetMap::const_iterator pos = map.find(lang);
+  if (pos != map.end()) {
+    *lang_set = pos->second;
+    return true;
+  }
+  return false;
+}
+
+void SetExemplarSetForLang(const std::string& lang,
+                           icu::UnicodeSet* lang_set) {
+  LangToExemplarSetMap& map = LangToExemplarSet::GetInstance()->map;
+  map.insert(std::make_pair(lang, lang_set));
+}
+
+static base::LazyInstance<base::Lock>::Leaky
+    g_lang_set_lock = LAZY_INSTANCE_INITIALIZER;
+
+// Returns true if all the characters in component_characters are used by
+// the language |lang|.
+bool IsComponentCoveredByLang(const icu::UnicodeSet& component_characters,
+                              const std::string& lang) {
+  CR_DEFINE_STATIC_LOCAL(
+      const icu::UnicodeSet, kASCIILetters, ('a', 'z'));
+  icu::UnicodeSet* lang_set = NULL;
+  // We're called from both the UI thread and the history thread.
+  {
+    base::AutoLock lock(g_lang_set_lock.Get());
+    if (!GetExemplarSetForLang(lang, &lang_set)) {
+      UErrorCode status = U_ZERO_ERROR;
+      ULocaleData* uld = ulocdata_open(lang.c_str(), &status);
+      // TODO(jungshik) Turn this check on when the ICU data file is
+      // rebuilt with the minimal subset of locale data for languages
+      // to which Chrome is not localized but which we offer in the list
+      // of languages selectable for Accept-Languages. With the rebuilt ICU
+      // data, ulocdata_open never should fall back to the default locale.
+      // (issue 2078)
+      // DCHECK(U_SUCCESS(status) && status != U_USING_DEFAULT_WARNING);
+      if (U_SUCCESS(status) && status != U_USING_DEFAULT_WARNING) {
+        lang_set = reinterpret_cast<icu::UnicodeSet *>(
+            ulocdata_getExemplarSet(uld, NULL, 0,
+                                    ULOCDATA_ES_STANDARD, &status));
+        // If |lang| is compatible with ASCII Latin letters, add them.
+        if (IsCompatibleWithASCIILetters(lang))
+          lang_set->addAll(kASCIILetters);
+      } else {
+        lang_set = new icu::UnicodeSet(1, 0);
+      }
+      lang_set->freeze();
+      SetExemplarSetForLang(lang, lang_set);
+      ulocdata_close(uld);
+    }
+  }
+  return !lang_set->isEmpty() && lang_set->containsAll(component_characters);
+}
+
+// Returns true if the given Unicode host component is safe to display to the
+// user.
+bool IsIDNComponentSafe(const base::char16* str,
+                        int str_len,
+                        const std::string& languages) {
+  // Most common cases (non-IDN) do not reach here so that we don't
+  // need a fast return path.
+  // TODO(jungshik) : Check if there's any character inappropriate
+  // (although allowed) for domain names.
+  // See http://www.unicode.org/reports/tr39/#IDN_Security_Profiles and
+  // http://www.unicode.org/reports/tr39/data/xidmodifications.txt
+  // For now, we borrow the list from Mozilla and tweaked it slightly.
+  // (e.g. Characters like U+00A0, U+3000, U+3002 are omitted because
+  //  they're gonna be canonicalized to U+0020 and full stop before
+  //  reaching here.)
+  // The original list is available at
+  // http://kb.mozillazine.org/Network.IDN.blacklist_chars and
+  // at http://mxr.mozilla.org/seamonkey/source/modules/libpref/src/init/all.js#703
+
+  UErrorCode status = U_ZERO_ERROR;
+#ifdef U_WCHAR_IS_UTF16
+  icu::UnicodeSet dangerous_characters(icu::UnicodeString(
+      L"[[\\ \u00ad\u00bc\u00bd\u01c3\u0337\u0338"
+      L"\u05c3\u05f4\u06d4\u0702\u115f\u1160][\u2000-\u200b]"
+      L"[\u2024\u2027\u2028\u2029\u2039\u203a\u2044\u205f]"
+      L"[\u2154-\u2156][\u2159-\u215b][\u215f\u2215\u23ae"
+      L"\u29f6\u29f8\u2afb\u2afd][\u2ff0-\u2ffb][\u3014"
+      L"\u3015\u3033\u3164\u321d\u321e\u33ae\u33af\u33c6\u33df\ufe14"
+      L"\ufe15\ufe3f\ufe5d\ufe5e\ufeff\uff0e\uff06\uff61\uffa0\ufff9]"
+      L"[\ufffa-\ufffd]]"), status);
+  DCHECK(U_SUCCESS(status));
+  icu::RegexMatcher dangerous_patterns(icu::UnicodeString(
+      // Lone katakana no, so, or n
+      L"[^\\p{Katakana}][\u30ce\u30f3\u30bd][^\\p{Katakana}]"
+      // Repeating Japanese accent characters
+      L"|[\u3099\u309a\u309b\u309c][\u3099\u309a\u309b\u309c]"),
+      0, status);
+#else
+  icu::UnicodeSet dangerous_characters(icu::UnicodeString(
+      "[[\\u0020\\u00ad\\u00bc\\u00bd\\u01c3\\u0337\\u0338"
+      "\\u05c3\\u05f4\\u06d4\\u0702\\u115f\\u1160][\\u2000-\\u200b]"
+      "[\\u2024\\u2027\\u2028\\u2029\\u2039\\u203a\\u2044\\u205f]"
+      "[\\u2154-\\u2156][\\u2159-\\u215b][\\u215f\\u2215\\u23ae"
+      "\\u29f6\\u29f8\\u2afb\\u2afd][\\u2ff0-\\u2ffb][\\u3014"
+      "\\u3015\\u3033\\u3164\\u321d\\u321e\\u33ae\\u33af\\u33c6\\u33df\\ufe14"
+      "\\ufe15\\ufe3f\\ufe5d\\ufe5e\\ufeff\\uff0e\\uff06\\uff61\\uffa0\\ufff9]"
+      "[\\ufffa-\\ufffd]]", -1, US_INV), status);
+  DCHECK(U_SUCCESS(status));
+  icu::RegexMatcher dangerous_patterns(icu::UnicodeString(
+      // Lone katakana no, so, or n
+      "[^\\p{Katakana}][\\u30ce\\u30f3\u30bd][^\\p{Katakana}]"
+      // Repeating Japanese accent characters
+      "|[\\u3099\\u309a\\u309b\\u309c][\\u3099\\u309a\\u309b\\u309c]"),
+      0, status);
+#endif
+  DCHECK(U_SUCCESS(status));
+  icu::UnicodeSet component_characters;
+  icu::UnicodeString component_string(str, str_len);
+  component_characters.addAll(component_string);
+  if (dangerous_characters.containsSome(component_characters))
+    return false;
+
+  DCHECK(U_SUCCESS(status));
+  dangerous_patterns.reset(component_string);
+  if (dangerous_patterns.find())
+    return false;
+
+  // If the language list is empty, the result is completely determined
+  // by whether a component is a single script or not. This will block
+  // even "safe" script mixing cases like <Chinese, Latin-ASCII> that are
+  // allowed with |languages| (while it blocks Chinese + Latin letters with
+  // an accent as should be the case), but we want to err on the safe side
+  // when |languages| is empty.
+  if (languages.empty())
+    return IsIDNComponentInSingleScript(str, str_len);
+
+  // |common_characters| is made up of  ASCII numbers, hyphen, plus and
+  // underscore that are used across scripts and allowed in domain names.
+  // (sync'd with characters allowed in url_canon_host with square
+  // brackets excluded.) See kHostCharLookup[] array in url_canon_host.cc.
+  icu::UnicodeSet common_characters(UNICODE_STRING_SIMPLE("[[0-9]\\-_+\\ ]"),
+                                    status);
+  DCHECK(U_SUCCESS(status));
+  // Subtract common characters because they're always allowed so that
+  // we just have to check if a language-specific set contains
+  // the remainder.
+  component_characters.removeAll(common_characters);
+
+  base::StringTokenizer t(languages, ",");
+  while (t.GetNext()) {
+    if (IsComponentCoveredByLang(component_characters, t.token()))
+      return true;
+  }
+  return false;
+}
+
+// A wrapper to use LazyInstance<>::Leaky with ICU's UIDNA, a C pointer to
+// a UTS46/IDNA 2008 handling object opened with uidna_openUTS46().
+//
+// We use UTS46 with BiDiCheck to migrate from IDNA 2003 to IDNA 2008 with
+// the backward compatibility in mind. What it does:
+//
+// 1. Use the up-to-date Unicode data.
+// 2. Define a case folding/mapping with the up-to-date Unicode data as
+//    in IDNA 2003.
+// 3. Use transitional mechanism for 4 deviation characters (sharp-s,
+//    final sigma, ZWJ and ZWNJ) for now.
+// 4. Continue to allow symbols and punctuations.
+// 5. Apply new BiDi check rules more permissive than the IDNA 2003 BiDI rules.
+// 6. Do not apply STD3 rules
+// 7. Do not allow unassigned code points.
+//
+// It also closely matches what IE 10 does except for the BiDi check (
+// http://goo.gl/3XBhqw ).
+// See http://http://unicode.org/reports/tr46/ and references therein
+// for more details.
+struct UIDNAWrapper {
+  UIDNAWrapper() {
+    UErrorCode err = U_ZERO_ERROR;
+    // TODO(jungshik): Change options as different parties (browsers,
+    // registrars, search engines) converge toward a consensus.
+    value = uidna_openUTS46(UIDNA_CHECK_BIDI, &err);
+    if (U_FAILURE(err))
+      value = NULL;
+  }
+
+  UIDNA* value;
+};
+
+static base::LazyInstance<UIDNAWrapper>::Leaky
+    g_uidna = LAZY_INSTANCE_INITIALIZER;
+
+// Converts one component of a host (between dots) to IDN if safe. The result
+// will be APPENDED to the given output string and will be the same as the input
+// if it is not IDN or the IDN is unsafe to display.  Returns whether any
+// conversion was performed.
+bool IDNToUnicodeOneComponent(const base::char16* comp,
+                              size_t comp_len,
+                              const std::string& languages,
+                              base::string16* out) {
+  DCHECK(out);
+  if (comp_len == 0)
+    return false;
+
+  // Only transform if the input can be an IDN component.
+  static const base::char16 kIdnPrefix[] = {'x', 'n', '-', '-'};
+  if ((comp_len > arraysize(kIdnPrefix)) &&
+      !memcmp(comp, kIdnPrefix, arraysize(kIdnPrefix) * sizeof(base::char16))) {
+    UIDNA* uidna = g_uidna.Get().value;
+    DCHECK(uidna != NULL);
+    size_t original_length = out->length();
+    int output_length = 64;
+    UIDNAInfo info = UIDNA_INFO_INITIALIZER;
+    UErrorCode status;
+    do {
+      out->resize(original_length + output_length);
+      status = U_ZERO_ERROR;
+      // This returns the actual length required. If this is more than 64
+      // code units, |status| will be U_BUFFER_OVERFLOW_ERROR and we'll try
+      // the conversion again, but with a sufficiently large buffer.
+      output_length = uidna_labelToUnicode(
+          uidna, comp, static_cast<int32_t>(comp_len), &(*out)[original_length],
+          output_length, &info, &status);
+    } while ((status == U_BUFFER_OVERFLOW_ERROR && info.errors == 0));
+
+    if (U_SUCCESS(status) && info.errors == 0) {
+      // Converted successfully. Ensure that the converted component
+      // can be safely displayed to the user.
+      out->resize(original_length + output_length);
+      if (IsIDNComponentSafe(out->data() + original_length, output_length,
+                             languages))
+        return true;
+    }
+
+    // Something went wrong. Revert to original string.
+    out->resize(original_length);
+  }
+
+  // We get here with no IDN or on error, in which case we just append the
+  // literal input.
+  out->append(comp, comp_len);
+  return false;
+}
+
+// Clamps the offsets in |offsets_for_adjustment| to the length of |str|.
+void LimitOffsets(const base::string16& str, Offsets* offsets_for_adjustment) {
+  if (offsets_for_adjustment) {
+    std::for_each(offsets_for_adjustment->begin(),
+                  offsets_for_adjustment->end(),
+                  base::LimitOffset<base::string16>(str.length()));
+  }
+}
+
+// TODO(brettw) bug 734373: check the scripts for each host component and
+// don't un-IDN-ize if there is more than one. Alternatively, only IDN for
+// scripts that the user has installed. For now, just put the entire
+// path through IDN. Maybe this feature can be implemented in ICU itself?
+//
+// We may want to skip this step in the case of file URLs to allow unicode
+// UNC hostnames regardless of encodings.
+base::string16 IDNToUnicodeWithOffsets(const std::string& host,
+                                       const std::string& languages,
+                                       Offsets* offsets_for_adjustment) {
+  // Convert the ASCII input to a base::string16 for ICU.
+  base::string16 input16;
+  input16.reserve(host.length());
+  input16.insert(input16.end(), host.begin(), host.end());
+
+  // Do each component of the host separately, since we enforce script matching
+  // on a per-component basis.
+  base::string16 out16;
+  {
+    base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
+    for (size_t component_start = 0, component_end;
+         component_start < input16.length();
+         component_start = component_end + 1) {
+      // Find the end of the component.
+      component_end = input16.find('.', component_start);
+      if (component_end == base::string16::npos)
+        component_end = input16.length();  // For getting the last component.
+      size_t component_length = component_end - component_start;
+      size_t new_component_start = out16.length();
+      bool converted_idn = false;
+      if (component_end > component_start) {
+        // Add the substring that we just found.
+        converted_idn = IDNToUnicodeOneComponent(
+            input16.data() + component_start, component_length, languages,
+            &out16);
+      }
+      size_t new_component_length = out16.length() - new_component_start;
+
+      if (converted_idn && offsets_for_adjustment) {
+        offset_adjuster.Add(base::OffsetAdjuster::Adjustment(component_start,
+            component_length, new_component_length));
+      }
+
+      // Need to add the dot we just found (if we found one).
+      if (component_end < input16.length())
+        out16.push_back('.');
+    }
+  }
+
+  LimitOffsets(out16, offsets_for_adjustment);
+  return out16;
+}
+
+// Called after transforming a component to set all affected elements in
+// |offsets_for_adjustment| to the correct new values.  |original_offsets|
+// represents the offsets before the transform; |original_component_begin| and
+// |original_component_end| represent the pre-transform boundaries of the
+// affected component.  |transformed_offsets| should be a vector created by
+// adjusting |original_offsets| to be relative to the beginning of the component
+// in question (via an OffsetAdjuster) and then transformed along with the
+// component.  Note that any elements in this vector which didn't originally
+// point into the component may contain arbitrary values and should be ignored.
+// |transformed_component_begin| and |transformed_component_end| are the
+// endpoints of the transformed component and are used in combination with the
+// two offset vectors to calculate the resulting absolute offsets, which are
+// stored in |offsets_for_adjustment|.
+void AdjustForComponentTransform(const Offsets& original_offsets,
+                                 size_t original_component_begin,
+                                 size_t original_component_end,
+                                 const Offsets& transformed_offsets,
+                                 size_t transformed_component_begin,
+                                 size_t transformed_component_end,
+                                 Offsets* offsets_for_adjustment) {
+  if (!offsets_for_adjustment)
+    return;  // Nothing to do.
+
+  for (size_t i = 0; i < original_offsets.size(); ++i) {
+    size_t original_offset = original_offsets[i];
+    if ((original_offset >= original_component_begin) &&
+        (original_offset < original_component_end)) {
+      // This offset originally pointed into the transformed component.
+      // Adjust the transformed relative offset by the new beginning point of
+      // the transformed component.
+      size_t transformed_offset = transformed_offsets[i];
+      (*offsets_for_adjustment)[i] =
+          (transformed_offset == base::string16::npos) ?
+              base::string16::npos :
+              (transformed_offset + transformed_component_begin);
+    } else if ((original_offset >= original_component_end) &&
+               (original_offset != std::string::npos)) {
+      // This offset pointed after the transformed component.  Adjust the
+      // original absolute offset by the difference between the new and old
+      // component lengths.
+      (*offsets_for_adjustment)[i] =
+          original_offset - original_component_end + transformed_component_end;
+    }
+  }
+}
+
+// If |component| is valid, its begin is incremented by |delta|.
+void AdjustComponent(int delta, url_parse::Component* component) {
+  if (!component->is_valid())
+    return;
+
+  DCHECK(delta >= 0 || component->begin >= -delta);
+  component->begin += delta;
+}
+
+// Adjusts all the components of |parsed| by |delta|, except for the scheme.
+void AdjustAllComponentsButScheme(int delta, url_parse::Parsed* parsed) {
+  AdjustComponent(delta, &(parsed->username));
+  AdjustComponent(delta, &(parsed->password));
+  AdjustComponent(delta, &(parsed->host));
+  AdjustComponent(delta, &(parsed->port));
+  AdjustComponent(delta, &(parsed->path));
+  AdjustComponent(delta, &(parsed->query));
+  AdjustComponent(delta, &(parsed->ref));
+}
+
+// Helper for FormatUrlWithOffsets().
+base::string16 FormatViewSourceUrl(const GURL& url,
+                                   const Offsets& original_offsets,
+                                   const std::string& languages,
+                                   FormatUrlTypes format_types,
+                                   UnescapeRule::Type unescape_rules,
+                                   url_parse::Parsed* new_parsed,
+                                   size_t* prefix_end,
+                                   Offsets* offsets_for_adjustment) {
+  DCHECK(new_parsed);
+  const char kViewSource[] = "view-source:";
+  const size_t kViewSourceLength = arraysize(kViewSource) - 1;
+
+  // Format the underlying URL and adjust offsets.
+  const std::string& url_str(url.possibly_invalid_spec());
+  Offsets offsets_into_underlying_url(original_offsets);
+  {
+    base::OffsetAdjuster adjuster(&offsets_into_underlying_url);
+    adjuster.Add(base::OffsetAdjuster::Adjustment(0, kViewSourceLength, 0));
+  }
+  base::string16 result(base::ASCIIToUTF16(kViewSource) +
+      FormatUrlWithOffsets(GURL(url_str.substr(kViewSourceLength)), languages,
+                           format_types, unescape_rules, new_parsed, prefix_end,
+                           &offsets_into_underlying_url));
+  AdjustForComponentTransform(original_offsets, kViewSourceLength,
+                              url_str.length(), offsets_into_underlying_url,
+                              kViewSourceLength, result.length(),
+                              offsets_for_adjustment);
+  LimitOffsets(result, offsets_for_adjustment);
+
+  // Adjust positions of the parsed components.
+  if (new_parsed->scheme.is_nonempty()) {
+    // Assume "view-source:real-scheme" as a scheme.
+    new_parsed->scheme.len += kViewSourceLength;
+  } else {
+    new_parsed->scheme.begin = 0;
+    new_parsed->scheme.len = kViewSourceLength - 1;
+  }
+  AdjustAllComponentsButScheme(kViewSourceLength, new_parsed);
+
+  if (prefix_end)
+    *prefix_end += kViewSourceLength;
+
+  return result;
+}
+
+class AppendComponentTransform {
+ public:
+  AppendComponentTransform() {}
+  virtual ~AppendComponentTransform() {}
+
+  virtual base::string16 Execute(const std::string& component_text,
+                                 Offsets* offsets_into_component) const = 0;
+
+  // NOTE: No DISALLOW_COPY_AND_ASSIGN here, since gcc < 4.3.0 requires an
+  // accessible copy constructor in order to call AppendFormattedComponent()
+  // with an inline temporary (see http://gcc.gnu.org/bugs/#cxx%5Frvalbind ).
+};
+
+class HostComponentTransform : public AppendComponentTransform {
+ public:
+  explicit HostComponentTransform(const std::string& languages)
+      : languages_(languages) {
+  }
+
+ private:
+  virtual base::string16 Execute(
+      const std::string& component_text,
+      Offsets* offsets_into_component) const OVERRIDE {
+    return IDNToUnicodeWithOffsets(component_text, languages_,
+                                   offsets_into_component);
+  }
+
+  const std::string& languages_;
+};
+
+class NonHostComponentTransform : public AppendComponentTransform {
+ public:
+  explicit NonHostComponentTransform(UnescapeRule::Type unescape_rules)
+      : unescape_rules_(unescape_rules) {
+  }
+
+ private:
+  virtual base::string16 Execute(
+      const std::string& component_text,
+      Offsets* offsets_into_component) const OVERRIDE {
+    return (unescape_rules_ == UnescapeRule::NONE) ?
+        base::UTF8ToUTF16AndAdjustOffsets(component_text,
+                                          offsets_into_component) :
+        UnescapeAndDecodeUTF8URLComponentWithOffsets(component_text,
+            unescape_rules_, offsets_into_component);
+  }
+
+  const UnescapeRule::Type unescape_rules_;
+};
+
+// Transforms the portion of |spec| covered by |original_component| according to
+// |transform|.  Appends the result to |output|.  If |output_component| is
+// non-NULL, its start and length are set to the transformed component's new
+// start and length.  For each element in |original_offsets| which is at least
+// as large as original_component.begin, the corresponding element of
+// |offsets_for_adjustment| is transformed appropriately.
+void AppendFormattedComponent(const std::string& spec,
+                              const url_parse::Component& original_component,
+                              const Offsets& original_offsets,
+                              const AppendComponentTransform& transform,
+                              base::string16* output,
+                              url_parse::Component* output_component,
+                              Offsets* offsets_for_adjustment) {
+  DCHECK(output);
+  if (original_component.is_nonempty()) {
+    size_t original_component_begin =
+        static_cast<size_t>(original_component.begin);
+    size_t output_component_begin = output->length();
+    std::string component_str(spec, original_component_begin,
+                              static_cast<size_t>(original_component.len));
+
+    // Transform |component_str| and adjust the offsets accordingly.
+    Offsets offsets_into_component(original_offsets);
+    {
+      base::OffsetAdjuster adjuster(&offsets_into_component);
+      adjuster.Add(base::OffsetAdjuster::Adjustment(0, original_component_begin,
+                                                    0));
+    }
+    output->append(transform.Execute(component_str, &offsets_into_component));
+    AdjustForComponentTransform(original_offsets, original_component_begin,
+                                static_cast<size_t>(original_component.end()),
+                                offsets_into_component, output_component_begin,
+                                output->length(), offsets_for_adjustment);
+
+    // Set positions of the parsed component.
+    if (output_component) {
+      output_component->begin = static_cast<int>(output_component_begin);
+      output_component->len =
+          static_cast<int>(output->length() - output_component_begin);
+    }
+  } else if (output_component) {
+    output_component->reset();
+  }
+}
+
+}  // namespace
+
+const FormatUrlType kFormatUrlOmitNothing                     = 0;
+const FormatUrlType kFormatUrlOmitUsernamePassword            = 1 << 0;
+const FormatUrlType kFormatUrlOmitHTTP                        = 1 << 1;
+const FormatUrlType kFormatUrlOmitTrailingSlashOnBareHostname = 1 << 2;
+const FormatUrlType kFormatUrlOmitAll = kFormatUrlOmitUsernamePassword |
+    kFormatUrlOmitHTTP | kFormatUrlOmitTrailingSlashOnBareHostname;
+
+base::string16 IDNToUnicode(const std::string& host,
+                            const std::string& languages) {
+  return IDNToUnicodeWithOffsets(host, languages, NULL);
+}
+
+std::string GetDirectoryListingEntry(const base::string16& name,
+                                     const std::string& raw_bytes,
+                                     bool is_dir,
+                                     int64 size,
+                                     Time modified) {
+  std::string result;
+  result.append("<script>addRow(");
+  base::EscapeJSONString(name, true, &result);
+  result.append(",");
+  if (raw_bytes.empty()) {
+    base::EscapeJSONString(EscapePath(base::UTF16ToUTF8(name)), true, &result);
+  } else {
+    base::EscapeJSONString(EscapePath(raw_bytes), true, &result);
+  }
+  if (is_dir) {
+    result.append(",1,");
+  } else {
+    result.append(",0,");
+  }
+
+  // Negative size means unknown or not applicable (e.g. directory).
+  base::string16 size_string;
+  if (size >= 0)
+    size_string = FormatBytesUnlocalized(size);
+  base::EscapeJSONString(size_string, true, &result);
+
+  result.append(",");
+
+  base::string16 modified_str;
+  // |modified| can be NULL in FTP listings.
+  if (!modified.is_null()) {
+    modified_str = base::TimeFormatShortDateAndTime(modified);
+  }
+  base::EscapeJSONString(modified_str, true, &result);
+
+  result.append(");</script>\n");
+
+  return result;
+}
+
+void AppendFormattedHost(const GURL& url,
+                         const std::string& languages,
+                         base::string16* output) {
+  Offsets offsets;
+  AppendFormattedComponent(url.possibly_invalid_spec(),
+      url.parsed_for_possibly_invalid_spec().host, offsets,
+      HostComponentTransform(languages), output, NULL, NULL);
+}
+
+base::string16 FormatUrlWithOffsets(
+    const GURL& url,
+    const std::string& languages,
+    FormatUrlTypes format_types,
+    UnescapeRule::Type unescape_rules,
+    url_parse::Parsed* new_parsed,
+    size_t* prefix_end,
+    Offsets* offsets_for_adjustment) {
+  url_parse::Parsed parsed_temp;
+  if (!new_parsed)
+    new_parsed = &parsed_temp;
+  else
+    *new_parsed = url_parse::Parsed();
+  Offsets original_offsets;
+  if (offsets_for_adjustment)
+    original_offsets = *offsets_for_adjustment;
+
+  // Special handling for view-source:.  Don't use content::kViewSourceScheme
+  // because this library shouldn't depend on chrome.
+  const char* const kViewSource = "view-source";
+  // Reject "view-source:view-source:..." to avoid deep recursion.
+  const char* const kViewSourceTwice = "view-source:view-source:";
+  if (url.SchemeIs(kViewSource) &&
+      !StartsWithASCII(url.possibly_invalid_spec(), kViewSourceTwice, false)) {
+    return FormatViewSourceUrl(url, original_offsets, languages, format_types,
+                               unescape_rules, new_parsed, prefix_end,
+                               offsets_for_adjustment);
+  }
+
+  // We handle both valid and invalid URLs (this will give us the spec
+  // regardless of validity).
+  const std::string& spec = url.possibly_invalid_spec();
+  const url_parse::Parsed& parsed = url.parsed_for_possibly_invalid_spec();
+
+  // Scheme & separators.  These are ASCII.
+  base::string16 url_string;
+  url_string.insert(url_string.end(), spec.begin(),
+      spec.begin() + parsed.CountCharactersBefore(url_parse::Parsed::USERNAME,
+                                                  true));
+  const char kHTTP[] = "http://";
+  const char kFTP[] = "ftp.";
+  // URLFixerUpper::FixupURL() treats "ftp.foo.com" as ftp://ftp.foo.com.  This
+  // means that if we trim "http://" off a URL whose host starts with "ftp." and
+  // the user inputs this into any field subject to fixup (which is basically
+  // all input fields), the meaning would be changed.  (In fact, often the
+  // formatted URL is directly pre-filled into an input field.)  For this reason
+  // we avoid stripping "http://" in this case.
+  bool omit_http = (format_types & kFormatUrlOmitHTTP) &&
+      EqualsASCII(url_string, kHTTP) &&
+      !StartsWithASCII(url.host(), kFTP, true);
+  new_parsed->scheme = parsed.scheme;
+
+  // Username & password.
+  if ((format_types & kFormatUrlOmitUsernamePassword) != 0) {
+    // Remove the username and password fields. We don't want to display those
+    // to the user since they can be used for attacks,
+    // e.g. "http://google.com:search@evil.ru/"
+    new_parsed->username.reset();
+    new_parsed->password.reset();
+    // Update the offsets based on removed username and/or password.
+    if (offsets_for_adjustment && !offsets_for_adjustment->empty() &&
+        (parsed.username.is_nonempty() || parsed.password.is_nonempty())) {
+      base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
+      if (parsed.username.is_nonempty() && parsed.password.is_nonempty()) {
+        // The seeming off-by-one and off-by-two in these first two lines are to
+        // account for the ':' after the username and '@' after the password.
+        offset_adjuster.Add(base::OffsetAdjuster::Adjustment(
+            static_cast<size_t>(parsed.username.begin),
+            static_cast<size_t>(parsed.username.len + parsed.password.len + 2),
+            0));
+      } else {
+        const url_parse::Component* nonempty_component =
+            parsed.username.is_nonempty() ? &parsed.username : &parsed.password;
+        // The seeming off-by-one in below is to account for the '@' after the
+        // username/password.
+        offset_adjuster.Add(base::OffsetAdjuster::Adjustment(
+            static_cast<size_t>(nonempty_component->begin),
+            static_cast<size_t>(nonempty_component->len + 1), 0));
+      }
+    }
+  } else {
+    AppendFormattedComponent(spec, parsed.username, original_offsets,
+        NonHostComponentTransform(unescape_rules), &url_string,
+        &new_parsed->username, offsets_for_adjustment);
+    if (parsed.password.is_valid())
+      url_string.push_back(':');
+    AppendFormattedComponent(spec, parsed.password, original_offsets,
+        NonHostComponentTransform(unescape_rules), &url_string,
+        &new_parsed->password, offsets_for_adjustment);
+    if (parsed.username.is_valid() || parsed.password.is_valid())
+      url_string.push_back('@');
+  }
+  if (prefix_end)
+    *prefix_end = static_cast<size_t>(url_string.length());
+
+  // Host.
+  AppendFormattedComponent(spec, parsed.host, original_offsets,
+      HostComponentTransform(languages), &url_string, &new_parsed->host,
+      offsets_for_adjustment);
+
+  // Port.
+  if (parsed.port.is_nonempty()) {
+    url_string.push_back(':');
+    new_parsed->port.begin = url_string.length();
+    url_string.insert(url_string.end(),
+                      spec.begin() + parsed.port.begin,
+                      spec.begin() + parsed.port.end());
+    new_parsed->port.len = url_string.length() - new_parsed->port.begin;
+  } else {
+    new_parsed->port.reset();
+  }
+
+  // Path & query.  Both get the same general unescape & convert treatment.
+  if (!(format_types & kFormatUrlOmitTrailingSlashOnBareHostname) ||
+      !CanStripTrailingSlash(url)) {
+    AppendFormattedComponent(spec, parsed.path, original_offsets,
+        NonHostComponentTransform(unescape_rules), &url_string,
+        &new_parsed->path, offsets_for_adjustment);
+  } else {
+    base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
+    offset_adjuster.Add(base::OffsetAdjuster::Adjustment(
+        url_string.length(), parsed.path.len, 0));
+  }
+  if (parsed.query.is_valid())
+    url_string.push_back('?');
+  AppendFormattedComponent(spec, parsed.query, original_offsets,
+      NonHostComponentTransform(unescape_rules), &url_string,
+      &new_parsed->query, offsets_for_adjustment);
+
+  // Ref.  This is valid, unescaped UTF-8, so we can just convert.
+  if (parsed.ref.is_valid())
+    url_string.push_back('#');
+  AppendFormattedComponent(spec, parsed.ref, original_offsets,
+      NonHostComponentTransform(UnescapeRule::NONE), &url_string,
+      &new_parsed->ref, offsets_for_adjustment);
+
+  // If we need to strip out http do it after the fact. This way we don't need
+  // to worry about how offset_for_adjustment is interpreted.
+  if (omit_http && StartsWith(url_string, base::ASCIIToUTF16(kHTTP), true)) {
+    const size_t kHTTPSize = arraysize(kHTTP) - 1;
+    url_string = url_string.substr(kHTTPSize);
+    if (offsets_for_adjustment && !offsets_for_adjustment->empty()) {
+      base::OffsetAdjuster offset_adjuster(offsets_for_adjustment);
+      offset_adjuster.Add(base::OffsetAdjuster::Adjustment(0, kHTTPSize, 0));
+    }
+    if (prefix_end)
+      *prefix_end -= kHTTPSize;
+
+    // Adjust new_parsed.
+    DCHECK(new_parsed->scheme.is_valid());
+    int delta = -(new_parsed->scheme.len + 3);  // +3 for ://.
+    new_parsed->scheme.reset();
+    AdjustAllComponentsButScheme(delta, new_parsed);
+  }
+
+  LimitOffsets(url_string, offsets_for_adjustment);
+  return url_string;
+}
+
+base::string16 FormatUrl(const GURL& url,
+                         const std::string& languages,
+                         FormatUrlTypes format_types,
+                         UnescapeRule::Type unescape_rules,
+                         url_parse::Parsed* new_parsed,
+                         size_t* prefix_end,
+                         size_t* offset_for_adjustment) {
+  Offsets offsets;
+  if (offset_for_adjustment)
+    offsets.push_back(*offset_for_adjustment);
+  base::string16 result = FormatUrlWithOffsets(url, languages, format_types,
+      unescape_rules, new_parsed, prefix_end, &offsets);
+  if (offset_for_adjustment)
+    *offset_for_adjustment = offsets[0];
+  return result;
+}
+
+}  // namespace net
diff --git a/net/net.gypi b/net/net.gypi
index 2fec5b6..795236c 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -43,6 +43,7 @@
       'base/net_module.h',
       'base/net_util.cc',
       'base/net_util.h',
+      'base/net_util_icu.cc',
       'base/net_util_posix.cc',
       'base/openssl_private_key_store.h',
       'base/openssl_private_key_store_android.cc',
diff --git a/net/tools/DEPS b/net/tools/DEPS
index 1ea12e4..4648a84 100644
--- a/net/tools/DEPS
+++ b/net/tools/DEPS
@@ -1,3 +1,7 @@
+include_rules = [
+  "+base/i18n",
+]
+
 skip_child_includes = [
   "balsa",
   "flip_server",
diff --git a/tools/gn/secondary/net/BUILD.gn b/tools/gn/secondary/net/BUILD.gn
index 01ab0c8..8aaf55d 100644
--- a/tools/gn/secondary/net/BUILD.gn
+++ b/tools/gn/secondary/net/BUILD.gn
@@ -121,6 +121,7 @@ component("net") {
     "base/net_module.h",
     "base/net_util.cc",
     "base/net_util.h",
+    "base/net_util_icu.cc",
     "base/net_util_posix.cc",
     "base/net_util_win.cc",
     "base/network_change_notifier.cc",