Clean up a few more unused globals.

chrome/browser/extensions/api/notifications/notifications_api.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/extensions/api/notifications/notifications_api.h"
 
 #include "base/callback.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
@@ skipping 18 matching lines @@
 #include "ui/message_center/message_center_util.h"
 #include "ui/message_center/notifier_settings.h"
 #include "url/gurl.h"
 
 namespace extensions {
 
 namespace notifications = api::notifications;
 
 namespace {
 
-const char kResultKey[] = "result";
 const char kMissingRequiredPropertiesForCreateNotification[] =
     "Some of the required properties are missing: type, iconUrl, title and "
     "message.";
 const char kUnexpectedProgressValueForNonProgressType[] =
     "The progress value should not be specified for non-progress notification";
 const char kInvalidProgressValue[] =
     "The progress value should range from 0 to 100";
 
 // Converts an object with width, height, and data in RGBA format into an
 // gfx::Image (in ARGB format).
@@ skipping 538 matching lines @@
         StripScopeFromIdentifier(extension_->id(), *iter), true);
   }
 
   SetResult(result.release());
   SendResponse(true);
 
   return true;
 }
 
 }  // namespace extensions