Move permission warning message handling from PermissionSet to PermissionMessageProvider.

extensions/common/permissions/permission_message_provider.cc

Index: extensions/common/permissions/permission_message_provider.cc
diff --git a/extensions/common/permissions/permission_message_provider.cc b/extensions/common/permissions/permission_message_provider.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5650eabfa3e8469829705d8bb43877b377cef96d
--- /dev/null
+++ b/extensions/common/permissions/permission_message_provider.cc
@@ -0,0 +1,16 @@
+// Copyright 2013 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 "extensions/common/permissions/permission_message_provider.h"
+
+#include "extensions/common/extensions_client.h"
+
+namespace extensions {
+
+// static
+const PermissionMessageProvider* PermissionMessageProvider::Get() {
+  return &(ExtensionsClient::Get()->GetPermissionMessageProvider());
+}
+
+}  // namespace extensions