extensions: clean up hiding/showing of developer controls.

chrome/browser/ui/webui/extensions/extension_settings_handler.cc

 // Copyright (c) 2012 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 "chrome/browser/ui/webui/extensions/extension_settings_handler.h"
 
 #include "apps/app_load_service.h"
 #include "apps/saved_files_service.h"
 #include "base/auto_reset.h"
 #include "base/base64.h"
@@ skipping 972 matching lines @@
         ->VerifyAllExtensions();
   }
 }
 
 void ExtensionSettingsHandler::HandleToggleDeveloperMode(
     const base::ListValue* args) {
   Profile* profile = Profile::FromWebUI(web_ui());
   if (profile->IsSupervised())
     return;
 
-  bool developer_mode =
-      !profile->GetPrefs()->GetBoolean(prefs::kExtensionsUIDeveloperMode);
+  bool developer_mode_on;
+  CHECK(args->GetBoolean(0, &developer_mode_on));
   profile->GetPrefs()->SetBoolean(prefs::kExtensionsUIDeveloperMode,
-                                  developer_mode);
+                                  developer_mode_on);
 }
 
 void ExtensionSettingsHandler::HandleInspectMessage(
     const base::ListValue* args) {
   std::string extension_id;
   std::string render_process_id_str;
   std::string render_view_id_str;
   int render_process_id;
   int render_view_id;
   bool incognito;
@@ skipping 523 matching lines @@
     extension_service_->EnableExtension(extension_id);
   } else {
     ExtensionErrorReporter::GetInstance()->ReportError(
         base::UTF8ToUTF16(JoinString(requirement_errors, ' ')),
         true);  // Be noisy.
   }
   requirements_checker_.reset();
 }
 
 }  // namespace extensions