Allow an empty list of page actions.

chrome/common/extensions/extension_constants.cc

 // Copyright (c) 2009 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_constants.h"
 
 namespace extension_manifest_keys {
 
 const wchar_t* kAllFrames = L"all_frames";
 const wchar_t* kBackground = L"background_page";
@@ skipping 104 matching lines @@
     "Required value 'name' is missing or invalid.";
 const char* kInvalidPageAction =
     "Invalid value for 'page_action'.";
 const char* kInvalidPageActionName =
     "Invalid value for 'page_action.name'.";
 const char* kInvalidPageActionIconPath =
     "Invalid value for 'page_action.default_icon'.";
 const char* kInvalidPageActionsList =
     "Invalid value for 'page_actions'.";
 const char* kInvalidPageActionsListSize =
-    "Invalid value for 'page_actions'. There can be only one.";
+    "Invalid value for 'page_actions'. There can be at most one page action.";
 const char* kInvalidPageActionId =
     "Required value 'id' is missing or invalid.";
 const char* kInvalidPageActionDefaultTitle =
     "Invalid value for 'default_title'.";
 const char* kInvalidPageActionPopup =
     "Invalid type for page action popup.";
 const char* kInvalidPageActionPopupHeight =
     "Invalid value for page action popup height [*].";
 const char* kInvalidPageActionPopupPath =
     "Invalid value for page action popup path [*].";
@@ skipping 69 matching lines @@
     "Invalid value for 'options_page'.";
 }  // namespace extension_manifest_errors
 
 namespace extension_urls {
 const char* kGalleryBrowsePrefix = "https://chrome.google.com/extensions";
 const char* kGalleryDownloadPrefix =
     "https://clients2.googleusercontent.com/crx/download";
 const char* kMiniGalleryBrowsePrefix = "https://tools.google.com/chrome/";
 const char* kMiniGalleryDownloadPrefix = "https://dl-ssl.google.com/chrome/";
 }