Add a preference to control Windows desktop search redirection.

components/search_engines/desktop_search_win.cc

Index: components/search_engines/desktop_search_win.cc
diff --git a/components/search_engines/detect_desktop_search_win.cc b/components/search_engines/desktop_search_win.cc
similarity index 63%
rename from components/search_engines/detect_desktop_search_win.cc
rename to components/search_engines/desktop_search_win.cc
index 563e80de7f16d668065bbfb24ea25e68aef1cadf..b1bae715aec628bed246e3d6fb02b5db1ac84b5b 100644
--- a/components/search_engines/detect_desktop_search_win.cc
+++ b/components/search_engines/desktop_search_win.cc
@@ -2,17 +2,42 @@
 // 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 <string>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/prefs/pref_service.h"
 #include "base/strings/string_util.h"
+#include "components/pref_registry/pref_registry_syncable.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"
 
+namespace prefs {
+const char kWindowsDesktopSearchRedirectionPref[] =
+    "windows_desktop_search_redirection";
+}  // namespace prefs
+
+const base::Feature kWindowsDesktopSearchRedirectionFeature = {
+    "WindowsDesktopSearchRedirection", base::FEATURE_DISABLED_BY_DEFAULT
+};
+
+void RegisterWindowsDesktopSearchRedirectionPref(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterBooleanPref(prefs::kWindowsDesktopSearchRedirectionPref,
+                                false);
+}
+
+bool ShouldRedirectWindowsDesktopSearchToDefaultSearchEngine(
+    PrefService* pref_service) {
+  DCHECK(pref_service);
+  return base::FeatureList::IsEnabled(
+             kWindowsDesktopSearchRedirectionFeature) &&
+         pref_service->GetBoolean(prefs::kWindowsDesktopSearchRedirectionPref);
+}
+
 bool DetectWindowsDesktopSearch(const GURL& url,
                                 const SearchTermsData& search_terms_data,
                                 base::string16* search_terms) {
@@ -37,7 +62,7 @@ bool DetectWindowsDesktopSearch(const GURL& url,
     // Use a case-insensitive comparison because the key is sometimes in capital
     // letters.
     if (base::EqualsCaseInsensitiveASCII(it.GetKey(), kBingSourceQueryKey)) {
-      std::string source = it.GetValue();
+      const std::string source = it.GetValue();
       if (source == kBingSourceDesktopText || source == kBingSourceDesktopVoice)
         return true;
     }