Disallow packing or loading unpacked manifest v1 extensions.

chrome/common/extensions/extension_manifest_constants.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/common/extensions/extension_manifest_constants.h"
 
 namespace extension_manifest_keys {
 
 const char kAllFrames[] = "all_frames";
 const char kAltKey[] = "altKey";
@@ skipping 311 matching lines @@
     " 'chromeos', 'linux' and 'default'.";
 const char kInvalidLaunchContainer[] =
     "Invalid value for 'app.launch.container'.";
 const char kInvalidLaunchValue[] =
     "Invalid value for '*'.";
 const char kInvalidLaunchValueContainer[] =
     "Invalid container type for '*'.";
 const char kInvalidManifest[] =
     "Manifest file is invalid.";
 const char kInvalidManifestVersion[] =
-    "The 'manifest_version' key must be present and set to 2 (without quotes).";
+    "Invalid value for 'manifest_version'. Must be an integer greater than zero.";
+const char kInvalidManifestVersionOld[] =
+    "The 'manifest_version' key must be present and set to 2 (without quotes). "
+    "See developer.chrome.com/extensions/manifestVersion.html for details.";
 const char kInvalidMatch[] =
     "Invalid value for 'content_scripts[*].matches[*]': *";
 const char kInvalidMatchCount[] =
     "Invalid value for 'content_scripts[*].matches'. There must be at least "
     "one match specified.";
 const char kInvalidMatches[] =
     "Required value 'content_scripts[*].matches' is missing or invalid.";
 const char kInvalidMinimumChromeVersion[] =
     "Invalid value for 'minimum_chrome_version'.";
 const char kInvalidName[] =
@@ skipping 152 matching lines @@
 const char kScriptBadgeTitleIgnored[] =
     "default_title specified in script_badge manifest section will not be "
     "used.";
 const char kWebRequestConflictsWithLazyBackground[] =
     "The 'webRequest' API cannot be used with event pages.";
 #if defined(OS_CHROMEOS)
 const char kIllegalPlugins[] =
     "Extensions cannot install plugins on Chrome OS";
 #endif
 }  // namespace extension_manifest_errors