Move most of the remaining users of WebContentsObserver::tab_contents() to use web_contents().

chrome/browser/translate/translate_tab_helper.cc

 // Copyright (c) 2011 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_tab_helper.h"
 
 #include "chrome/browser/translate/page_translated_details.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/render_messages.h"
 #include "content/browser/tab_contents/tab_contents.h"
 #include "content/public/browser/notification_service.h"
 
+using content::WebContents;
+
 TranslateTabHelper::TranslateTabHelper(TabContents* tab_contents)
     : content::WebContentsObserver(tab_contents),
       language_state_(&tab_contents->GetController()) {
 }
 
 TranslateTabHelper::~TranslateTabHelper() {
 }
 
 bool TranslateTabHelper::OnMessageReceived(const IPC::Message& message) {
   bool handled = true;
@@ skipping 14 matching lines @@
   language_state_.DidNavigate(details);
 }
 
 void TranslateTabHelper::OnLanguageDetermined(const std::string& language,
                                               bool page_translatable) {
   language_state_.LanguageDetermined(language, page_translatable);
 
   std::string lang = language;
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_TAB_LANGUAGE_DETERMINED,
-      content::Source<TabContents>(tab_contents()),
+      content::Source<WebContents>(web_contents()),
       content::Details<std::string>(&lang));
 }
 
 void TranslateTabHelper::OnPageTranslated(int32 page_id,
                                           const std::string& original_lang,
                                           const std::string& translated_lang,
                                           TranslateErrors::Type error_type) {
   language_state_.set_current_language(translated_lang);
   language_state_.set_translation_pending(false);
   PageTranslatedDetails details(original_lang, translated_lang, error_type);
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_PAGE_TRANSLATED,
-      content::Source<TabContents>(tab_contents()),
+      content::Source<WebContents>(web_contents()),
       content::Details<PageTranslatedDetails>(&details));
 }