Copy the implementations of TranslateUIDelegate to TransalteInfobarDelegate

TranslateInfobarDelegate won't own a WebContents by https://codereview.chromium.org/22694006/, while TranslateUIDelegate's implementation relies on the existence of a WebContents. Thus, I copied a part of implementations of TranslateUIDelegate to TranslteInfobarDelegate.

BUG=62154
TEST=browser_test --gtest_filter=TranslateManagerBrowserTest.*

Review URL: https://codereview.chromium.org/64823005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234759 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 244 insertions, 95 deletions

diff --git a/chrome/browser/translate/translate_browser_metrics.cc b/chrome/browser/translate/translate_browser_metrics.cc
index a6605bd..89f6133 100644
--- a/chrome/browser/translate/translate_browser_metrics.cc
+++ b/chrome/browser/translate/translate_browser_metrics.cc
@@ -25,6 +25,14 @@ const char kTranslateUndisplayableLanguage[] =
     "Translate.UndisplayableLanguage";
 const char kTranslateUnsupportedLanguageAtInitiation[] =
     "Translate.UnsupportedLanguageAtInitiation";
+const char kTranslateDeclineTranslate[] = "Translate.DeclineTranslate";
+const char kTranslateRevertTranslation[] = "Translate.RevertTranslation";
+const char kTranslatePerformTranslate[] = "Translate.Translate";
+const char kTranslateNeverTranslateLang[] = "Translate.NeverTranslateLang";
+const char kTranslateNeverTranslateSite[] = "Translate.NeverTranslateSite";
+const char kTranslateAlwaysTranslateLang[] = "Translate.AlwaysTranslateLang";
+const char kTranslateModifyOriginalLang[] = "Translate.ModifyOriginalLang";
+const char kTranslateModifyTargetLang[] = "Translate.ModifyTargetLang";
 
 struct MetricsEntry {
   TranslateBrowserMetrics::MetricsNameIndex index;
@@ -43,6 +51,22 @@ const MetricsEntry kMetricsEntries[] = {
     kTranslateUndisplayableLanguage },
   { TranslateBrowserMetrics::UMA_UNSUPPORTED_LANGUAGE_AT_INITIATION,
     kTranslateUnsupportedLanguageAtInitiation },
+  { TranslateBrowserMetrics::UMA_DECLINE_TRANSLATE,
+    kTranslateDeclineTranslate },
+  { TranslateBrowserMetrics::UMA_REVERT_TRANSLATION,
+    kTranslateRevertTranslation },
+  { TranslateBrowserMetrics::UMA_PERFORM_TRANSLATE,
+    kTranslatePerformTranslate },
+  { TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_LANG,
+    kTranslateNeverTranslateLang },
+  { TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_SITE,
+    kTranslateNeverTranslateSite },
+  { TranslateBrowserMetrics::UMA_ALWAYS_TRANSLATE_LANG,
+    kTranslateAlwaysTranslateLang },
+  { TranslateBrowserMetrics::UMA_MODIFY_ORIGINAL_LANG,
+    kTranslateModifyOriginalLang },
+  { TranslateBrowserMetrics::UMA_MODIFY_TARGET_LANG,
+    kTranslateModifyTargetLang },
 };
 
 COMPILE_ASSERT(arraysize(kMetricsEntries) == TranslateBrowserMetrics::UMA_MAX,
diff --git a/chrome/browser/translate/translate_browser_metrics.h b/chrome/browser/translate/translate_browser_metrics.h
index 21ee89d..475b76e 100644
--- a/chrome/browser/translate/translate_browser_metrics.h
+++ b/chrome/browser/translate/translate_browser_metrics.h
@@ -17,6 +17,14 @@ enum MetricsNameIndex {
   UMA_LOCALES_ON_DISABLED_BY_PREFS,
   UMA_UNDISPLAYABLE_LANGUAGE,
   UMA_UNSUPPORTED_LANGUAGE_AT_INITIATION,
+  UMA_DECLINE_TRANSLATE,
+  UMA_REVERT_TRANSLATION,
+  UMA_PERFORM_TRANSLATE,
+  UMA_NEVER_TRANSLATE_LANG,
+  UMA_NEVER_TRANSLATE_SITE,
+  UMA_ALWAYS_TRANSLATE_LANG,
+  UMA_MODIFY_ORIGINAL_LANG,
+  UMA_MODIFY_TARGET_LANG,
   UMA_MAX,
 };
 
diff --git a/chrome/browser/translate/translate_infobar_delegate.cc b/chrome/browser/translate/translate_infobar_delegate.cc
index c5e7044..aaaf65e 100644
--- a/chrome/browser/translate/translate_infobar_delegate.cc
+++ b/chrome/browser/translate/translate_infobar_delegate.cc
@@ -13,8 +13,10 @@
 #include "chrome/browser/infobars/infobar_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/translate/translate_accept_languages.h"
+#include "chrome/browser/translate/translate_browser_metrics.h"
 #include "chrome/browser/translate/translate_manager.h"
 #include "chrome/browser/translate/translate_tab_helper.h"
+#include "chrome/browser/translate/translate_ui_delegate.h"
 #include "components/translate/common/translate_constants.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/navigation_entry.h"
@@ -27,6 +29,7 @@
 using content::NavigationEntry;
 
 namespace {
+
 const char kCloseInfobar[] = "Translate.DeclineTranslateCloseInfobar";
 const char kShowErrorInfobar[] = "Translate.ShowErrorInfobar";
 
@@ -99,20 +102,42 @@ void TranslateInfoBarDelegate::Create(
 
 void TranslateInfoBarDelegate::UpdateOriginalLanguageIndex(
     size_t language_index) {
-  ui_delegate_.UpdateOriginalLanguageIndex(language_index);
+  if (original_language_index_ == language_index)
+    return;
+
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_MODIFY_ORIGINAL_LANG), true);
+  original_language_index_ = language_index;
 }
 
 void TranslateInfoBarDelegate::UpdateTargetLanguageIndex(
     size_t language_index) {
-  ui_delegate_.UpdateTargetLanguageIndex(language_index);
+  if (target_language_index_ == language_index)
+    return;
+
+  DCHECK_LT(language_index, num_languages());
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_MODIFY_TARGET_LANG), true);
+  target_language_index_ = language_index;
 }
 
 void TranslateInfoBarDelegate::Translate() {
-  ui_delegate_.Translate();
+  if (!web_contents()->GetBrowserContext()->IsOffTheRecord()) {
+    prefs_.ResetTranslationDeniedCount(original_language_code());
+    prefs_.IncrementTranslationAcceptedCount(original_language_code());
+  }
+  TranslateManager::GetInstance()->TranslatePage(web_contents(),
+                                                 original_language_code(),
+                                                 target_language_code());
+
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_PERFORM_TRANSLATE), true);
 }
 
 void TranslateInfoBarDelegate::RevertTranslation() {
-  ui_delegate_.RevertTranslation();
+  TranslateManager::GetInstance()->RevertTranslation(web_contents());
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_REVERT_TRANSLATION), true);
   RemoveSelf();
 }
 
@@ -122,7 +147,21 @@ void TranslateInfoBarDelegate::ReportLanguageDetectionError() {
 }
 
 void TranslateInfoBarDelegate::TranslationDeclined() {
-  ui_delegate_.TranslationDeclined();
+  if (!web_contents()->GetBrowserContext()->IsOffTheRecord()) {
+    prefs_.ResetTranslationAcceptedCount(original_language_code());
+    prefs_.IncrementTranslationDeniedCount(original_language_code());
+  }
+
+  // Remember that the user declined the translation so as to prevent showing a
+  // translate infobar for that page again.  (TranslateManager initiates
+  // translations when getting a LANGUAGE_DETERMINED from the page, which
+  // happens when a load stops. That could happen multiple times, including
+  // after the user already declined the translation.)
+  TranslateTabHelper::FromWebContents(web_contents())->
+      language_state().set_translation_declined(true);
+
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_DECLINE_TRANSLATE), true);
 }
 
 bool TranslateInfoBarDelegate::IsTranslatableLanguageByPrefs() {
@@ -134,44 +173,83 @@ bool TranslateInfoBarDelegate::IsTranslatableLanguageByPrefs() {
 }
 
 void TranslateInfoBarDelegate::ToggleTranslatableLanguageByPrefs() {
-  if (ui_delegate_.IsLanguageBlocked()) {
-    ui_delegate_.SetLanguageBlocked(false);
+  if (prefs_.IsBlockedLanguage(original_language_code())) {
+    prefs_.UnblockLanguage(original_language_code());
   } else {
-    ui_delegate_.SetLanguageBlocked(true);
+    prefs_.BlockLanguage(original_language_code());
+    TranslateTabHelper* translate_tab_helper =
+        TranslateTabHelper::FromWebContents(web_contents());
+    DCHECK(translate_tab_helper);
+    translate_tab_helper->language_state().SetTranslateEnabled(false);
     RemoveSelf();
   }
+
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_LANG), true);
 }
 
 bool TranslateInfoBarDelegate::IsSiteBlacklisted() {
-  return ui_delegate_.IsSiteBlacklisted();
+  std::string host = TranslateUIDelegate::GetPageHost(web_contents());
+  return !host.empty() && prefs_.IsSiteBlacklisted(host);
 }
 
 void TranslateInfoBarDelegate::ToggleSiteBlacklist() {
-  if (ui_delegate_.IsSiteBlacklisted()) {
-    ui_delegate_.SetSiteBlacklist(false);
+  std::string host = TranslateUIDelegate::GetPageHost(web_contents());
+  if (host.empty())
+    return;
+
+  if (prefs_.IsSiteBlacklisted(host)) {
+    prefs_.RemoveSiteFromBlacklist(host);
   } else {
-    ui_delegate_.SetSiteBlacklist(true);
+    prefs_.BlacklistSite(host);
+    TranslateTabHelper* translate_tab_helper =
+        TranslateTabHelper::FromWebContents(web_contents());
+    DCHECK(translate_tab_helper);
+    translate_tab_helper->language_state().SetTranslateEnabled(false);
     RemoveSelf();
   }
+
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_SITE), true);
 }
 
 bool TranslateInfoBarDelegate::ShouldAlwaysTranslate() {
-  return ui_delegate_.ShouldAlwaysTranslate();
+  return prefs_.IsLanguagePairWhitelisted(original_language_code(),
+                                          target_language_code());
 }
 
 void TranslateInfoBarDelegate::ToggleAlwaysTranslate() {
-  ui_delegate_.SetAlwaysTranslate(!ui_delegate_.ShouldAlwaysTranslate());
+  const std::string& original_lang = original_language_code();
+  const std::string& target_lang = target_language_code();
+  if (prefs_.IsLanguagePairWhitelisted(original_lang, target_lang))
+    prefs_.RemoveLanguagePairFromWhitelist(original_lang, target_lang);
+  else
+    prefs_.WhitelistLanguagePair(original_lang, target_lang);
+
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_ALWAYS_TRANSLATE_LANG), true);
 }
 
 void TranslateInfoBarDelegate::AlwaysTranslatePageLanguage() {
-  DCHECK(!ui_delegate_.ShouldAlwaysTranslate());
-  ui_delegate_.SetAlwaysTranslate(true);
+  const std::string& original_lang = original_language_code();
+  const std::string& target_lang = target_language_code();
+  DCHECK(!prefs_.IsLanguagePairWhitelisted(original_lang, target_lang));
+  prefs_.WhitelistLanguagePair(original_lang, target_lang);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_ALWAYS_TRANSLATE_LANG), true);
+
   Translate();
 }
 
 void TranslateInfoBarDelegate::NeverTranslatePageLanguage() {
-  DCHECK(!ui_delegate_.IsLanguageBlocked());
-  ui_delegate_.SetLanguageBlocked(true);
+  prefs_.BlockLanguage(original_language_code());
+  TranslateTabHelper* translate_tab_helper =
+      TranslateTabHelper::FromWebContents(web_contents());
+  DCHECK(translate_tab_helper);
+  translate_tab_helper->language_state().SetTranslateEnabled(false);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_LANG), true);
+
   RemoveSelf();
 }
 
@@ -305,7 +383,8 @@ TranslateInfoBarDelegate::TranslateInfoBarDelegate(
     : InfoBarDelegate(infobar_service),
       infobar_type_(infobar_type),
       background_animation_(NONE),
-      ui_delegate_(web_contents(), original_language, target_language),
+      original_language_index_(kNoIndex),
+      target_language_index_(kNoIndex),
       error_type_(error_type),
       prefs_(prefs),
       shortcut_config_(shortcut_config) {
@@ -314,6 +393,18 @@ TranslateInfoBarDelegate::TranslateInfoBarDelegate(
 
   if (old_delegate && (old_delegate->is_error() != is_error()))
     background_animation_ = is_error() ? NORMAL_TO_ERROR : ERROR_TO_NORMAL;
+
+  languages_ = TranslateUIDelegate::GetSortedLanguageNames(
+      g_browser_process->GetApplicationLocale());
+
+  for (std::vector<LanguageNamePair>::const_iterator iter = languages_.begin();
+       iter != languages_.end(); ++iter) {
+    std::string language_code = iter->first;
+    if (language_code == original_language)
+      original_language_index_ = iter - languages_.begin();
+    if (language_code == target_language)
+      target_language_index_ = iter - languages_.begin();
+  }
 }
 
 void TranslateInfoBarDelegate::InfoBarDismissed() {
diff --git a/chrome/browser/translate/translate_infobar_delegate.h b/chrome/browser/translate/translate_infobar_delegate.h
index dde0aa5..5f14e05 100644
--- a/chrome/browser/translate/translate_infobar_delegate.h
+++ b/chrome/browser/translate/translate_infobar_delegate.h
@@ -13,7 +13,6 @@
 #include "base/logging.h"
 #include "chrome/browser/infobars/infobar_delegate.h"
 #include "chrome/browser/translate/translate_prefs.h"
-#include "chrome/browser/translate/translate_ui_delegate.h"
 #include "chrome/common/translate/translate_errors.h"
 #include "components/translate/common/translate_constants.h"
 
@@ -26,6 +25,8 @@ struct ShortcutConfiguration {
   int never_translate_min_count;
 };
 
+// NOTE: TranslateUIDelegate should be updated if this implementation is
+// updated.
 class TranslateInfoBarDelegate : public InfoBarDelegate {
  public:
   // The different types of infobars that can be shown for translation.
@@ -70,38 +71,45 @@ class TranslateInfoBarDelegate : public InfoBarDelegate {
                      const ShortcutConfiguration& shortcut_config);
 
   // Returns the number of languages supported.
-  size_t num_languages() const { return ui_delegate_.GetNumberOfLanguages(); }
+  size_t num_languages() const {
+
+    return languages_.size();
+  }
 
   // Returns the ISO code for the language at |index|.
   std::string language_code_at(size_t index) const {
-    return ui_delegate_.GetLanguageCodeAt(index);
+    DCHECK_LT(index, num_languages());
+    return languages_[index].first;
   }
 
   // Returns the displayable name for the language at |index|.
   string16 language_name_at(size_t index) const {
-    return ui_delegate_.GetLanguageNameAt(index);
+    if (index == static_cast<size_t>(kNoIndex))
+      return string16();
+    DCHECK_LT(index, num_languages());
+    return languages_[index].second;
   }
 
   Type infobar_type() const { return infobar_type_; }
 
   TranslateErrors::Type error_type() const { return error_type_; }
 
-  size_t original_language_index() const {
-    return ui_delegate_.GetOriginalLanguageIndex();
-  }
+  size_t original_language_index() const { return original_language_index_; }
+
   void UpdateOriginalLanguageIndex(size_t language_index);
 
-  size_t target_language_index() const {
-    return ui_delegate_.GetTargetLanguageIndex();
-  }
+  size_t target_language_index() const { return target_language_index_; }
+
   void UpdateTargetLanguageIndex(size_t language_index);
 
   // Convenience methods.
   std::string original_language_code() const {
-    return ui_delegate_.GetOriginalLanguageCode();
+    return (original_language_index() == static_cast<size_t>(kNoIndex)) ?
+        translate::kUnknownLanguageCode :
+        language_code_at(original_language_index());
   }
   std::string target_language_code() const {
-    return ui_delegate_.GetTargetLanguageCode();
+    return language_code_at(target_language_index());
   }
 
   // Returns true if the current infobar indicates an error (in which case it
@@ -199,7 +207,14 @@ class TranslateInfoBarDelegate : public InfoBarDelegate {
   // infobar.
   BackgroundAnimationType background_animation_;
 
-  TranslateUIDelegate ui_delegate_;
+  // The list of the languages supported for translation.
+  std::vector<LanguageNamePair> languages_;
+
+  // The index of the webpage's original language.
+  size_t original_language_index_;
+
+  // The index of the language the webpage will be translated into.
+  size_t target_language_index_;
 
   // The error that occurred when trying to translate (NONE if no error).
   TranslateErrors::Type error_type_;
diff --git a/chrome/browser/translate/translate_manager_browsertest.cc b/chrome/browser/translate/translate_manager_browsertest.cc
index afffdda..5546efa 100644
--- a/chrome/browser/translate/translate_manager_browsertest.cc
+++ b/chrome/browser/translate/translate_manager_browsertest.cc
@@ -24,6 +24,7 @@
 #include "chrome/browser/translate/translate_prefs.h"
 #include "chrome/browser/translate/translate_script.h"
 #include "chrome/browser/translate/translate_tab_helper.h"
+#include "chrome/browser/translate/translate_ui_delegate.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/translate/translate_bubble_factory.h"
diff --git a/chrome/browser/translate/translate_ui_delegate.cc b/chrome/browser/translate/translate_ui_delegate.cc
index ee2f009..4e40115 100644
--- a/chrome/browser/translate/translate_ui_delegate.cc
+++ b/chrome/browser/translate/translate_ui_delegate.cc
@@ -8,6 +8,7 @@
 #include "base/metrics/histogram.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/translate/translate_browser_metrics.h"
 #include "chrome/browser/translate/translate_manager.h"
 #include "chrome/browser/translate/translate_prefs.h"
 #include "chrome/browser/translate/translate_tab_helper.h"
@@ -18,70 +19,74 @@
 #include "third_party/icu/source/i18n/unicode/coll.h"
 #include "ui/base/l10n/l10n_util.h"
 
-namespace {
-
-const char kDeclineTranslate[] = "Translate.DeclineTranslate";
-const char kRevertTranslation[] = "Translate.RevertTranslation";
-const char kPerformTranslate[] = "Translate.Translate";
-const char kNeverTranslateLang[] = "Translate.NeverTranslateLang";
-const char kNeverTranslateSite[] = "Translate.NeverTranslateSite";
-const char kAlwaysTranslateLang[] = "Translate.AlwaysTranslateLang";
-const char kModifyOriginalLang[] = "Translate.ModifyOriginalLang";
-const char kModifyTargetLang[] = "Translate.ModifyTargetLang";
-
-}  // namespace
-
 TranslateUIDelegate::TranslateUIDelegate(content::WebContents* web_contents,
                                          const std::string& original_language,
                                          const std::string& target_language)
     : web_contents_(web_contents),
       original_language_index_(NO_INDEX),
-      initial_original_language_index_(NO_INDEX),
       target_language_index_(NO_INDEX) {
+  languages_ =
+      GetSortedLanguageNames(g_browser_process->GetApplicationLocale());
+
+  for (std::vector<LanguageNamePair>::const_iterator iter = languages_.begin();
+       iter != languages_.end(); ++iter) {
+    std::string language_code = iter->first;
+    if (language_code == original_language)
+      original_language_index_ = iter - languages_.begin();
+    if (language_code == target_language)
+      target_language_index_ = iter - languages_.begin();
+  }
+
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents->GetBrowserContext());
+  prefs_.reset(new TranslatePrefs(profile->GetPrefs()));
+}
+
+TranslateUIDelegate::~TranslateUIDelegate() {
+}
+
+// static
+std::vector<TranslateUIDelegate::LanguageNamePair>
+    TranslateUIDelegate::GetSortedLanguageNames(const std::string& locale) {
   std::vector<std::string> language_codes;
   TranslateManager::GetSupportedLanguages(&language_codes);
 
   // Preparing for the alphabetical order in the locale.
   UErrorCode error = U_ZERO_ERROR;
-  std::string locale = g_browser_process->GetApplicationLocale();
   icu::Locale loc(locale.c_str());
   scoped_ptr<icu::Collator> collator(icu::Collator::createInstance(loc, error));
   collator->setStrength(icu::Collator::PRIMARY);
 
-  languages_.reserve(language_codes.size());
+  std::vector<LanguageNamePair> language_names;
+  language_names.reserve(language_codes.size());
   for (std::vector<std::string>::const_iterator iter = language_codes.begin();
        iter != language_codes.end(); ++iter) {
     std::string language_code = *iter;
 
     string16 language_name = l10n_util::GetDisplayNameForLocale(
-        language_code, g_browser_process->GetApplicationLocale(), true);
-    // Insert the language in languages_ in alphabetical order.
+        language_code, locale, true);
+    // Insert the language in |language_names| in alphabetical order.
     std::vector<LanguageNamePair>::iterator iter2;
-    for (iter2 = languages_.begin(); iter2 != languages_.end(); ++iter2) {
+    for (iter2 = language_names.begin(); iter2 != language_names.end();
+         ++iter2) {
       if (base::i18n::CompareString16WithCollator(collator.get(),
           language_name, iter2->second) == UCOL_LESS) {
         break;
       }
     }
-    languages_.insert(iter2, LanguageNamePair(language_code, language_name));
-  }
-  for (std::vector<LanguageNamePair>::const_iterator iter = languages_.begin();
-       iter != languages_.end(); ++iter) {
-    std::string language_code = iter->first;
-    if (language_code == original_language) {
-      original_language_index_ = iter - languages_.begin();
-      initial_original_language_index_ = original_language_index_;
-    }
-    if (language_code == target_language)
-      target_language_index_ = iter - languages_.begin();
+    language_names.insert(iter2,
+                          LanguageNamePair(language_code, language_name));
   }
 
-  Profile* profile =
-      Profile::FromBrowserContext(web_contents->GetBrowserContext());
-  prefs_.reset(new TranslatePrefs(profile->GetPrefs()));
+  return language_names;
 }
 
-TranslateUIDelegate::~TranslateUIDelegate() {
+// static
+std::string TranslateUIDelegate::GetPageHost(
+    content::WebContents* web_contents) {
+  content::NavigationEntry* entry =
+      web_contents->GetController().GetActiveEntry();
+  return entry ? entry->GetURL().HostNoBrackets() : std::string();
 }
 
 size_t TranslateUIDelegate::GetNumberOfLanguages() const {
@@ -96,7 +101,8 @@ void TranslateUIDelegate::UpdateOriginalLanguageIndex(size_t language_index) {
   if (original_language_index_ == language_index)
     return;
 
-  UMA_HISTOGRAM_BOOLEAN(kModifyOriginalLang, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_MODIFY_ORIGINAL_LANG), true);
   original_language_index_ = language_index;
 }
 
@@ -109,7 +115,8 @@ void TranslateUIDelegate::UpdateTargetLanguageIndex(size_t language_index) {
     return;
 
   DCHECK_LT(language_index, GetNumberOfLanguages());
-  UMA_HISTOGRAM_BOOLEAN(kModifyTargetLang, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_MODIFY_TARGET_LANG), true);
   target_language_index_ = language_index;
 }
 
@@ -145,13 +152,15 @@ void TranslateUIDelegate::Translate() {
                                                  GetOriginalLanguageCode(),
                                                  GetTargetLanguageCode());
 
-  UMA_HISTOGRAM_BOOLEAN(kPerformTranslate, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_PERFORM_TRANSLATE), true);
 }
 
 void TranslateUIDelegate::RevertTranslation() {
   TranslateManager::GetInstance()->RevertTranslation(web_contents());
 
-  UMA_HISTOGRAM_BOOLEAN(kRevertTranslation, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_REVERT_TRANSLATION), true);
 }
 
 void TranslateUIDelegate::TranslationDeclined() {
@@ -168,7 +177,8 @@ void TranslateUIDelegate::TranslationDeclined() {
   TranslateTabHelper::FromWebContents(web_contents())->
       language_state().set_translation_declined(true);
 
-  UMA_HISTOGRAM_BOOLEAN(kDeclineTranslate, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_DECLINE_TRANSLATE), true);
 }
 
 bool TranslateUIDelegate::IsLanguageBlocked() {
@@ -186,16 +196,17 @@ void TranslateUIDelegate::SetLanguageBlocked(bool value) {
     prefs_->UnblockLanguage(GetOriginalLanguageCode());
   }
 
-  UMA_HISTOGRAM_BOOLEAN(kNeverTranslateLang, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_LANG), true);
 }
 
 bool TranslateUIDelegate::IsSiteBlacklisted() {
-  std::string host = GetPageHost();
+  std::string host = GetPageHost(web_contents());
   return !host.empty() && prefs_->IsSiteBlacklisted(host);
 }
 
 void TranslateUIDelegate::SetSiteBlacklist(bool value) {
-  std::string host = GetPageHost();
+  std::string host = GetPageHost(web_contents());
   if (host.empty())
     return;
 
@@ -209,7 +220,8 @@ void TranslateUIDelegate::SetSiteBlacklist(bool value) {
     prefs_->RemoveSiteFromBlacklist(host);
   }
 
-  UMA_HISTOGRAM_BOOLEAN(kNeverTranslateSite, true);
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_NEVER_TRANSLATE_SITE), true);
 }
 
 bool TranslateUIDelegate::ShouldAlwaysTranslate() {
@@ -225,11 +237,6 @@ void TranslateUIDelegate::SetAlwaysTranslate(bool value) {
   else
     prefs_->RemoveLanguagePairFromWhitelist(original_lang, target_lang);
 
-  UMA_HISTOGRAM_BOOLEAN(kAlwaysTranslateLang, true);
-}
-
-std::string TranslateUIDelegate::GetPageHost() {
-  content::NavigationEntry* entry =
-      web_contents()->GetController().GetActiveEntry();
-  return entry ? entry->GetURL().HostNoBrackets() : std::string();
+  UMA_HISTOGRAM_BOOLEAN(TranslateBrowserMetrics::GetMetricsName(
+      TranslateBrowserMetrics::UMA_ALWAYS_TRANSLATE_LANG), true);
 }
diff --git a/chrome/browser/translate/translate_ui_delegate.h b/chrome/browser/translate/translate_ui_delegate.h
index 656b6d2..5345c82 100644
--- a/chrome/browser/translate/translate_ui_delegate.h
+++ b/chrome/browser/translate/translate_ui_delegate.h
@@ -21,17 +21,33 @@ class WebContents;
 
 // The TranslateUIDelegate is a generic delegate for UI which offers Translate
 // feature to the user.
+//
+// Note: TranslateInfobarDelegate should be updated if this implementation is
+// updated.
 class TranslateUIDelegate {
  public:
   enum {
     NO_INDEX = -1,
   };
 
+  // A pair whose key is a language code and value is the language's
+  // displayable name.
+  typedef std::pair<std::string, string16> LanguageNamePair;
+
   TranslateUIDelegate(content::WebContents* web_contents,
                       const std::string& original_language,
                       const std::string& target_language);
   virtual ~TranslateUIDelegate();
 
+  // Retrieves the displayable names of the supported languages, based on
+  // |locale|. The returned names are sorted in alphabetical order.
+  static std::vector<LanguageNamePair> GetSortedLanguageNames(
+      const std::string& locale);
+
+  // Gets the host of the page of |web_contents|, or an empty string if no URL
+  // is associated with the current page.
+  static std::string GetPageHost(content::WebContents* web_contents);
+
   content::WebContents* web_contents() { return web_contents_; }
 
   // Returns the number of languages supported.
@@ -91,14 +107,8 @@ class TranslateUIDelegate {
   void SetAlwaysTranslate(bool value);
 
  private:
-  // Gets the host of the page being translated, or an empty string if no URL is
-  // associated with the current page.
-  std::string GetPageHost();
-
   content::WebContents* web_contents_;
 
-  typedef std::pair<std::string, string16> LanguageNamePair;
-
   // The list supported languages for translation.
   // The pair first string is the language ISO code (ex: en, fr...), the second
   // string is the displayable name on the current locale.
@@ -108,13 +118,6 @@ class TranslateUIDelegate {
   // The index for language the page is originally in.
   size_t original_language_index_;
 
-  // The index for language the page is originally in that was originally
-  // reported (original_language_index_ changes if the user selects a new
-  // original language, but this one does not).  This is necessary to report
-  // language detection errors with the right original language even if the user
-  // changed the original language.
-  size_t initial_original_language_index_;
-
   // The index for language the page should be translated to.
   size_t target_language_index_;