Make sure Shared Modules cannot be disabled

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2013 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/browser/extensions/extension_service.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <iterator>
@@ skipping 851 matching lines @@
   if (extension_prefs_->IsExtensionBlacklisted(extension_id))
     return;
 
   // The extension may have been disabled already. Just add the disable reasons.
   if (!IsExtensionEnabled(extension_id)) {
     extension_prefs_->AddDisableReasons(extension_id, disable_reasons);
     return;
   }
 
   const Extension* extension = GetInstalledExtension(extension_id);
+
+  // Shared modules cannot be disabled, they are just resources used by other
+  // extensions, and are not user controlled.
+  if (extension && SharedModuleInfo::IsSharedModule(extension))
+    return;
+
   // |extension| can be nullptr if sync disables an extension that is not
   // installed yet.
   // EXTERNAL_COMPONENT extensions are not generally modifiable by users, but
   // can be uninstalled by the browser if the user sets extension-specific
   // preferences.
   if (extension && !(disable_reasons & Extension::DISABLE_RELOAD) &&
       !(disable_reasons & Extension::DISABLE_UPDATE_REQUIRED_BY_POLICY) &&
       !system_->management_policy()->UserMayModifySettings(extension,
                                                            nullptr) &&
       extension->location() != Manifest::EXTERNAL_COMPONENT) {
@@ skipping 531 matching lines @@
   content::NotificationService::current()->Notify(
       extensions::NOTIFICATION_EXTENSIONS_READY_DEPRECATED,
       content::Source<Profile>(profile_),
       content::NotificationService::NoDetails());
 }
 
 void ExtensionService::OnLoadedInstalledExtensions() {
   if (updater_)
     updater_->Start();
 
+  // Enable any Shared Modules that incorrectly got disabled previously.
+  // This is temporary code to fix incorrect behavior from previous versions of
+  // Chrome and can be removed after several releases (perhaps M60).
+  extensions::ExtensionList to_enable;
+  for (const auto& extension : registry_->disabled_extensions()) {
+    if (SharedModuleInfo::IsSharedModule(extension.get()))
+      to_enable.push_back(extension);
+  }
+  for (const auto& extension : to_enable) {
+    EnableExtension(extension->id());
+  }
+
   OnBlacklistUpdated();
 }
 
 void ExtensionService::AddExtension(const Extension* extension) {
   // TODO(jstritar): We may be able to get rid of this branch by overriding the
   // default extension state to DISABLED when the --disable-extensions flag
   // is set (http://crbug.com/29067).
   if (!extensions_enabled() &&
       !extension->is_theme() &&
       extension->location() != Manifest::COMPONENT &&
@@ skipping 1015 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }