Extensions: Make it possible for permission parsing code to return a detailed error message.

extensions/common/manifest_constants.h

Index: extensions/common/manifest_constants.h
===================================================================
--- extensions/common/manifest_constants.h	(revision 247036)
+++ extensions/common/manifest_constants.h	(working copy)
@@ -222,7 +222,7 @@
 extern const char kRunAtDocumentIdle[];
 extern const char kRunAtDocumentStart[];
 
-}  // manifest_values
+}  // namespace manifest_values
 
 // Error messages returned from extension installation.
 namespace manifest_errors {
@@ -375,6 +375,7 @@
 extern const char kInvalidPageActionsList[];
 extern const char kInvalidPageActionsListSize[];
 extern const char kInvalidPageActionTypeValue[];
+extern const char kInvalidPermissionWithDetail[];
 extern const char kInvalidPermission[];
 extern const char kInvalidPermissions[];
 extern const char kInvalidPermissionScheme[];