override chrome:// URLs via extensions.

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* kBackground = L"background_page";
+const wchar_t* kChromeURLOverrides = L"chrome_url_overrides";
 const wchar_t* kContentScripts = L"content_scripts";
 const wchar_t* kCss = L"css";
 const wchar_t* kDefaultLocale = L"default_locale";
 const wchar_t* kDescription = L"description";
 const wchar_t* kIcons = L"icons";
 const wchar_t* kJs = L"js";
 const wchar_t* kMatches = L"matches";
 const wchar_t* kName = L"name";
 const wchar_t* kPageActionId = L"id";
 const wchar_t* kPageActions = L"page_actions";
@@ skipping 25 matching lines @@
 const char* kRunAtDocumentEnd = "document_end";
 const char* kPageActionTypeTab = "tab";
 const char* kPageActionTypePermanent = "permanent";
 }  // namespace extension_manifest_values
 
 // Extension-related error messages. Some of these are simple patterns, where a
 // '*' is replaced at runtime with a specific value. This is used instead of
 // printf because we want to unit test them and scanf is hard to make
 // cross-platform.
 namespace extension_manifest_errors {
+const char* kInvalidChromeURLOverrides =
+    "Invalid value for 'chrome_url_overrides'.";
 const char* kInvalidContentScript =
     "Invalid value for 'content_scripts[*]'.";
 const char* kInvalidContentScriptsList =
     "Invalid value for 'content_scripts'.";
 const char* kInvalidCss =
     "Invalid value for 'content_scripts[*].css[*]'.";
 const char* kInvalidCssList =
     "Required value 'content_scripts[*].css is invalid.";
 const char* kInvalidDescription =
     "Invalid value for 'description'.";
@@ skipping 80 matching lines @@
     "Invalid value for update url: '[*]'.";
 const char* kInvalidDefaultLocale =
     "Invalid value for default locale - locale name must be a string.";
 const char* kThemesCannotContainExtensions =
     "A theme cannot contain extensions code.";
 const char* kLocalesNoDefaultLocaleSpecified =
     "Localization used, but default_locale wasn't specified in the manifest.";
 const char* kLocalesNoValidLocaleNamesListed =
     "No valid locale name could be found in _locales directory.";
 }  // namespace extension_manifest_errors