Add a group policy controlling which sites can install extensions.

chrome/common/pref_names.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/pref_names.h"
 
 #include "base/basictypes.h"
 
 namespace prefs {
 
@@ skipping 1322 matching lines @@
 const char kDisableExtensions[] = "extensions.disabled";
 
 // Whether the plugin finder that lets you install missing plug-ins is enabled.
 const char kDisablePluginFinder[] = "plugins.disable_plugin_finder";
 
 // Integer boolean representing the width (in pixels) of the container for
 // browser actions.
 const char kBrowserActionContainerWidth[] =
     "extensions.browseractions.container.width";
 
+// The sites that are allowed to install extensions. These sites should be
+// allowed to install extensions without the scary dangerous downloads bar.
+// Also, when off-store-extension installs are disabled, these sites are exempt.

[Yoyo Zhou, 2012/06/07 19:19:15]

Should this say "this is controlled by the administrator" like the two below?

[Aaron Boodman, 2012/06/07 22:37:11]

The ones below aren't strictly true. I mean anyone can set the pref, if they
edit the file. I don't think it makes sense to mention the administrator here...
that's a separate system. I'll just remove it from the other two.

+const char kExtensionAllowedInstallSites[] = "extensions.allowed_install_sites";
+
 // A whitelist of extension ids the user can install: exceptions from the
 // following blacklist. This is controlled by the administrator.
 const char kExtensionInstallAllowList[] = "extensions.install.allowlist";
+
 // A blacklist, containing extensions the user cannot install. This list can
 // conatin "*" meaning all extensions. This is controlled by the administrator.
 // This list should not be confused with the extension blacklist, which is
 // Google controlled.
 const char kExtensionInstallDenyList[] = "extensions.install.denylist";
 
 // Whether we have run the extension-alert system (see ExtensionGlobalError)
 // at least once for this profile.
 const char kExtensionAlertsInitializedPref[] = "extensions.alerts.initialized";
 
@@ skipping 555 matching lines @@
 const char kInManagedMode[] = "managed_mode";
 
 // Counts how many more times the 'profile on a network share' warning should be
 // shown to the user before the next silence period.
 const char kNetworkProfileWarningsLeft[] = "network_profile.warnings_left";
 // Tracks the time of the last shown warning. Used to reset
 // |network_profile.warnings_left| after a silence period.
 const char kNetworkProfileLastWarningTime[] =
     "network_profile.last_warning_time";
 }  // namespace prefs