Hack to restrict runtime API to dev channel rather than experimental.

chrome/common/extensions/extension_permission_set.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_permission_set.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/command_line.h"
@@ skipping 33 matching lines @@
 const char* kNonPermissionModuleNames[] = {
   "app",
   "browserAction",
   "devtools",
   "extension",
   "i18n",
   "omnibox",
   "pageAction",
   "pageActions",
   "permissions",
+  "runtime",
   "test",
   "types"
 };
 const size_t kNumNonPermissionModuleNames =
     arraysize(kNonPermissionModuleNames);
 
 // Names of functions (within modules requiring permissions) that can be used
 // without asking for the module permission. In other words, functions you can
 // use with no permissions specified.
 const char* kNonPermissionFunctionNames[] = {
@@ skipping 898 matching lines @@
   ExtensionOAuth2Scopes current_scopes = scopes();
   ExtensionOAuth2Scopes new_scopes = permissions->scopes();
   ExtensionOAuth2Scopes delta_scopes;
   std::set_difference(new_scopes.begin(), new_scopes.end(),
                       current_scopes.begin(), current_scopes.end(),
                       std::inserter(delta_scopes, delta_scopes.begin()));
 
   // We have less privileges if there are additional scopes present.
   return !delta_scopes.empty();
 }