[WebView] Remove more redundant classes

android_webview/browser/aw_locale_manager.h

 // Copyright 2015 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.
 
 #ifndef ANDROID_WEBVIEW_BROWSER_AW_LOCALE_MANAGER_H_
 #define ANDROID_WEBVIEW_BROWSER_AW_LOCALE_MANAGER_H_
 
 #include <string>
 
 #include "base/macros.h"
 
 namespace android_webview {
 
-// Empty base class so this can be destroyed by AwContentBrowserClient.
 class AwLocaleManager {
  public:
-  AwLocaleManager() {}
-  virtual ~AwLocaleManager() {}
+  AwLocaleManager() = default;
+  ~AwLocaleManager() = default;
 
-  virtual std::string GetLocale() = 0;
+  std::string GetLocale();
 
-  virtual std::string GetLocaleList() = 0;
+  std::string GetLocaleList();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AwLocaleManager);
 };
 
 }  // namespace android_webview
 
 #endif  // ANDROID_WEBVIEW_BROWSER_AW_LOCALE_MANAGER_H_