chrome: Cleanup class/struct forward declarations

chrome/browser/ui/search_engines/search_engine_tab_helper.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_SEARCH_ENGINES_SEARCH_ENGINE_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_SEARCH_ENGINES_SEARCH_ENGINE_TAB_HELPER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/ui/find_bar/find_bar_controller.h"
 #include "chrome/browser/ui/find_bar/find_notification_details.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
-class TemplateURL;
-
 // Per-tab search engine manager. Handles dealing search engine processing
 // functionality.
 class SearchEngineTabHelper
     : public content::WebContentsObserver,
       public content::WebContentsUserData<SearchEngineTabHelper> {
  public:
   ~SearchEngineTabHelper() override;
 
   // content::WebContentsObserver overrides.
   void DidFinishNavigation(content::NavigationHandle* handle) override;
 
   bool OnMessageReceived(const IPC::Message& message) override;
   bool OnMessageReceived(const IPC::Message& message,
                          content::RenderFrameHost* rfh) override;
 
  private:
   explicit SearchEngineTabHelper(content::WebContents* web_contents);
   friend class content::WebContentsUserData<SearchEngineTabHelper>;
 
   // Handles when a page specifies an OSDD (OpenSearch Description Document).
   void OnPageHasOSDD(const GURL& page_url, const GURL& osdd_url);
 
   // If params has a searchable form, this tries to create a new keyword.
   void GenerateKeywordIfNecessary(content::NavigationHandle* handle);
 
   DISALLOW_COPY_AND_ASSIGN(SearchEngineTabHelper);
 };
 
 #endif  // CHROME_BROWSER_UI_SEARCH_ENGINES_SEARCH_ENGINE_TAB_HELPER_H_