Add a preference to control Windows desktop search redirection.

components/search_engines/desktop_search_win_unittest.cc

Index: components/search_engines/desktop_search_win_unittest.cc
diff --git a/components/search_engines/detect_desktop_search_win_unittest.cc b/components/search_engines/desktop_search_win_unittest.cc
similarity index 65%
copy from components/search_engines/detect_desktop_search_win_unittest.cc
copy to components/search_engines/desktop_search_win_unittest.cc
index e3477a6ef0ef1e888621e59ff8dd492dae8c9025..5d873c5ab4623a08bdb055ef439dd8afda755636 100644
--- a/components/search_engines/detect_desktop_search_win_unittest.cc
+++ b/components/search_engines/desktop_search_win_unittest.cc
@@ -2,11 +2,12 @@
 // 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 "components/search_engines/desktop_search_win.h"
 
 #include "base/macros.h"
 #include "base/strings/string16.h"
 #include "components/search_engines/testing_search_terms_data.h"
+#include "components/syncable_prefs/testing_pref_service_syncable.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "url/gurl.h"
 
@@ -17,7 +18,24 @@ struct DetectWindowsDesktopSearchTestData {
 };
 }  // namespace
 
-TEST(DetectWindowsDesktopSearch, DetectWindowsDesktopSearch) {
+TEST(WindowsDesktopSearch, Prefs) {
+  const char kWindowsDesktopSearchRedirectionPref[] =
+      "windows_desktop_search_redirection";
+
+  syncable_prefs::TestingPrefServiceSyncable prefs;
+  RegisterWindowsDesktopSearchRedirectionPref(prefs.registry());
+
+  EXPECT_EQ(WindowsDesktopSearchRedirectionPref::UNSET,
+            GetWindowsDesktopSearchRedirectionPref(&prefs));
+  prefs.SetBoolean(kWindowsDesktopSearchRedirectionPref, true);
+  EXPECT_EQ(WindowsDesktopSearchRedirectionPref::ENABLED,
+            GetWindowsDesktopSearchRedirectionPref(&prefs));
+  prefs.SetBoolean(kWindowsDesktopSearchRedirectionPref, false);
+  EXPECT_EQ(WindowsDesktopSearchRedirectionPref::DISABLED,
+            GetWindowsDesktopSearchRedirectionPref(&prefs));
+}
+
+TEST(WindowsDesktopSearch, DetectWindowsDesktopSearch) {
   const DetectWindowsDesktopSearchTestData test_data[] = {
       {"https://www.google.com", L""},
       {"https://www.bing.com/search", L""},