Add a preference to control Windows desktop search redirection.

components/search_engines/detect_desktop_search_win.cc

-// 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.
-
-#include "components/search_engines/detect_desktop_search_win.h"
-
-#include <string>
-
-#include "base/memory/scoped_ptr.h"
-#include "base/strings/string_util.h"
-#include "components/search_engines/prepopulated_engines.h"
-#include "components/search_engines/template_url.h"
-#include "components/search_engines/template_url_prepopulate_data.h"
-#include "net/base/url_util.h"
-
-bool DetectWindowsDesktopSearch(const GURL& url,
-                                const SearchTermsData& search_terms_data,
-                                base::string16* search_terms) {
-  DCHECK(search_terms);
-
-  scoped_ptr<TemplateURLData> template_url_data =
-      TemplateURLPrepopulateData::MakeTemplateURLDataFromPrepopulatedEngine(
-          TemplateURLPrepopulateData::bing);
-  TemplateURL template_url(*template_url_data);
-
-  if (!template_url.ExtractSearchTermsFromURL(url, search_terms_data,
-                                              search_terms))
-    return false;
-
-  // Query parameter that tells the source of a Bing search URL, and values
-  // associated with Windows desktop search.
-  const char kBingSourceQueryKey[] = "form";
-  const char kBingSourceDesktopText[] = "WNSGPH";
-  const char kBingSourceDesktopVoice[] = "WNSBOX";
-
-  for (net::QueryIterator it(url); !it.IsAtEnd(); it.Advance()) {
-    // Use a case-insensitive comparison because the key is sometimes in capital
-    // letters.
-    if (base::EqualsCaseInsensitiveASCII(it.GetKey(), kBingSourceQueryKey)) {
-      std::string source = it.GetValue();
-      if (source == kBingSourceDesktopText || source == kBingSourceDesktopVoice)
-        return true;
-    }
-  }
-
-  search_terms->clear();
-  return false;
-}