Make BrowserMainParts have an empty implementation to make embedding easier.

chrome/browser/ui/views/chrome_browser_main_extra_parts_views.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/ui/views/chrome_browser_main_extra_parts_views.h"
 
 #include "chrome/browser/chrome_browser_main.h"
 #include "chrome/browser/toolkit_extra_parts.h"
 #include "chrome/browser/ui/views/chrome_views_delegate.h"
 
-ChromeBrowserMainExtraPartsViews::ChromeBrowserMainExtraPartsViews()
-    : ChromeBrowserMainExtraParts() {
+ChromeBrowserMainExtraPartsViews::ChromeBrowserMainExtraPartsViews() {
 }
 
 void ChromeBrowserMainExtraPartsViews::ToolkitInitialized() {
   // The delegate needs to be set before any UI is created so that windows
   // display the correct icon.
   if (!views::ViewsDelegate::views_delegate)
     views::ViewsDelegate::views_delegate = new ChromeViewsDelegate;
 }
 
 namespace browser {
 
 void AddViewsToolkitExtraParts(ChromeBrowserMainParts* main_parts) {
   main_parts->AddParts(new ChromeBrowserMainExtraPartsViews());
 }
 
 }  // namespace browser