Group the different permission related methods in the content api.

content/public/browser/permission_type.h

+// Copyright 2014 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.
+
+#ifndef CONTENT_PUBLIC_BROWSER_PERMISSION_TYPE_H_
+#define CONTENT_PUBLIC_BROWSER_PERMISSION_TYPE_H_
+
+namespace content {
+
+// This enum is also used for UMA purposes, so it needs to adhere to
+// the UMA guidelines.
+// Make sure you update histograms.xml if you add new permission types.
+// Never delete or reorder an entry; only add new entries
+// immediately before PERMISSION_NUM
+enum PermissionType {
+  PERMISSION_MIDI_SYSEX = 1,
+  PERMISSION_PUSH_MESSAGING = 2,
+  PERMISSION_NOTIFICATIONS = 3,
+  PERMISSION_GEOLOCATION = 4,
+  PERMISSION_PROTECTED_MEDIA = 5,
+
+  // Always keep this at the end.
+  PERMISSION_NUM,
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_PERMISSION_TYPE_H_