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

chrome/browser/automation/testing_automation_provider.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/automation/testing_automation_provider.h"
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 4085 matching lines @@
 
   TabLanguageDeterminedObserver* observer = new TabLanguageDeterminedObserver(
       this, reply_message, tab_contents, translate_bar);
   // If the language for the page hasn't been loaded yet, then just make
   // the observer, otherwise call observe directly.
   TranslateTabHelper* helper = TabContentsWrapper::GetCurrentWrapperForContents(
       tab_contents)->translate_tab_helper();
   std::string language = helper->language_state().original_language();
   if (!language.empty()) {
     observer->Observe(chrome::NOTIFICATION_TAB_LANGUAGE_DETERMINED,
-                      content::Source<TabContents>(tab_contents),
+                      content::Source<WebContents>(tab_contents),
                       content::Details<std::string>(&language));
   }
 }
 
 // See SelectTranslateOption() in chrome/test/pyautolib/pyauto.py for sample
 // json input.
 // Sample json output: {}
 void TestingAutomationProvider::SelectTranslateOption(
     Browser* browser,
     DictionaryValue* args,
@@ skipping 2557 matching lines @@
 
   Send(reply_message_);
   redirect_query_ = 0;
   reply_message_ = NULL;
 }
 
 void TestingAutomationProvider::OnRemoveProvider() {
   if (g_browser_process)
     g_browser_process->GetAutomationProviderList()->RemoveProvider(this);
 }