Split ExtensionSystem interface from ExtensionSystemImpl implementation, part 1.

chrome/browser/extensions/api/web_navigation/web_navigation_api.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.
 
 // Implements the Chrome Extensions WebNavigation API.
 
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api.h"
 
 #include "base/lazy_instance.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api_constants.h"
 #include "chrome/browser/extensions/api/web_navigation/web_navigation_api_helpers.h"
-#include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/extension_tab_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tab_contents/retargeting_details.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_iterator.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/common/extensions/api/web_navigation.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_request_details.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/url_constants.h"
 #include "extensions/browser/event_router.h"
+#include "extensions/browser/extension_system.h"
 #include "extensions/browser/view_type_utils.h"
 #include "net/base/net_errors.h"
 
 namespace GetFrame = extensions::api::web_navigation::GetFrame;
 namespace GetAllFrames = extensions::api::web_navigation::GetAllFrames;
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(extensions::WebNavigationTabObserver);
 
 namespace extensions {
 
@@ skipping 797 matching lines @@
 }
 
 void WebNavigationAPI::OnListenerAdded(const EventListenerInfo& details) {
   web_navigation_event_router_.reset(new WebNavigationEventRouter(profile_));
   ExtensionSystem::Get(profile_)->event_router()->UnregisterObserver(this);
 }
 
 #endif  // OS_ANDROID
 
 }  // namespace extensions