Move language detection to a component

chrome/browser/translate/translate_infobar_delegate.cc

 // 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 "chrome/browser/translate/translate_infobar_delegate.h"
 
 #include <algorithm>
 
 #include "base/i18n/string_compare.h"
 #include "base/metrics/histogram.h"
@@ skipping 44 matching lines @@
     PrefService* prefs,
     const ShortcutConfiguration& shortcut_config) {
   // Check preconditions.
   if (infobar_type != TRANSLATION_ERROR) {
     DCHECK(TranslateManager::IsSupportedLanguage(target_language));
     if (!TranslateManager::IsSupportedLanguage(original_language)) {
       // The original language can only be "unknown" for the "translating"
       // infobar, which is the case when the user started a translation from the
       // context menu.
       DCHECK(infobar_type == TRANSLATING || infobar_type == AFTER_TRANSLATE);
-      DCHECK_EQ(chrome::kUnknownLanguageCode, original_language);
+      DCHECK_EQ(translate::kUnknownLanguageCode, original_language);
     }
   }
 
   // Find any existing translate infobar delegate.
   TranslateInfoBarDelegate* old_delegate = NULL;
   for (size_t i = 0; i < infobar_service->infobar_count(); ++i) {
     old_delegate = infobar_service->infobar_at(i)->AsTranslateInfoBarDelegate();
     if (old_delegate) {
       if (!replace_existing_infobar)
         return;
@@ skipping 348 matching lines @@
 
 TranslateInfoBarDelegate*
     TranslateInfoBarDelegate::AsTranslateInfoBarDelegate() {
   return this;
 }
 
 std::string TranslateInfoBarDelegate::GetPageHost() {
   NavigationEntry* entry = web_contents()->GetController().GetActiveEntry();
   return entry ? entry->GetURL().HostNoBrackets() : std::string();
 }