Add GTK support for global Extension Commands

extensions/common/manifest_constants.h

 // 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.
 
 #ifndef EXTENSIONS_COMMON_MANIFEST_CONSTANTS_H_
 #define EXTENSIONS_COMMON_MANIFEST_CONSTANTS_H_
 
 namespace extensions {
 
 // Keys used in JSON representation of extensions.
@@ skipping 29 matching lines @@
 extern const char kExcludeMatches[];
 extern const char kExport[];
 extern const char kExternallyConnectable[];
 extern const char kFileAccessList[];
 extern const char kFileHandlers[];
 extern const char kFileHandlerExtensions[];
 extern const char kFileHandlerTitle[];
 extern const char kFileHandlerTypes[];
 extern const char kFileFilters[];
 extern const char kFileBrowserHandlers[];
+extern const char kGlobal[];
 extern const char kMediaGalleriesHandlers[];
 extern const char kHomepageURL[];
 extern const char kIcons[];
 extern const char kId[];
 extern const char kImport[];
 extern const char kIncognito[];
 extern const char kIncludeGlobs[];
 extern const char kInputComponents[];
 extern const char kIntentDisposition[];
 extern const char kIntentHref[];
@@ skipping 370 matching lines @@
 extern const char kWebRequestConflictsWithLazyBackground[];
 #if defined(OS_CHROMEOS)
 extern const char kIllegalPlugins[];
 #endif
 
 }  // namespace manifest_errors
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_MANIFEST_CONSTANTS_H_