Implement the Windows desktop search redirection feature.

components/search_engines/desktop_search_win.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 COMPONENTS_SEARCH_ENGINES_DESKTOP_SEARCH_WIN_H_
-#define COMPONENTS_SEARCH_ENGINES_DESKTOP_SEARCH_WIN_H_
-
-#include "base/feature_list.h"
-#include "base/strings/string16.h"
-
-class GURL;
-class PrefService;
-class SearchTermsData;
-
-namespace user_prefs {
-class PrefRegistrySyncable;
-}
-
-namespace prefs {
-// Name of the Windows desktop search redirection preference.
-extern const char kWindowsDesktopSearchRedirectionPref[];
-}
-
-// Windows desktop search redirection feature. This is exposed in the header
-// file so that it can be referenced from about_flags.cc.
-extern const base::Feature kWindowsDesktopSearchRedirectionFeature;
-
-// Registers the Windows desktop search redirection preference into |registry|.
-void RegisterWindowsDesktopSearchRedirectionPref(
-    user_prefs::PrefRegistrySyncable* registry);
-
-// Indicates whether Windows desktop searches should be redirected to the
-// default search engine. This is only true when both the preference and the
-// feature are enabled. The preference value is read from |pref_service|.
-bool ShouldRedirectWindowsDesktopSearchToDefaultSearchEngine(
-    PrefService* pref_service);
-
-// Detects whether a URL comes from a Windows Desktop search. If so, puts the
-// search terms in |search_terms| and returns true.
-bool DetectWindowsDesktopSearch(const GURL& url,
-                                const SearchTermsData& search_terms_data,
-                                base::string16* search_terms);
-
-#endif  // COMPONENTS_SEARCH_ENGINES_DESKTOP_SEARCH_WIN_H_