[DRAFT] Allow a user to revert to their previous theme without closing infobar

chrome/browser/themes/theme_syncable_service.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/browser/themes/theme_syncable_service.h"
 
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 190 matching lines @@
 }
 
 void ThemeSyncableService::SetCurrentThemeFromThemeSpecifics(
     const sync_pb::ThemeSpecifics& theme_specifics) {
   if (theme_specifics.use_custom_theme()) {
     // TODO(akalin): Figure out what to do about third-party themes
     // (i.e., those not on either Google gallery).
     string id(theme_specifics.custom_theme_id());
     GURL update_url(theme_specifics.custom_theme_update_url());
     DVLOG(1) << "Applying theme " << id << " with update_url " << update_url;
-    ExtensionServiceInterface* extensions_service =
+    ExtensionService* extensions_service =
         extensions::ExtensionSystem::Get(profile_)->extension_service();
     CHECK(extensions_service);
     const extensions::Extension* extension =
         extensions_service->GetExtensionById(id, true);
     if (extension) {
       if (!extension->is_theme()) {
         DVLOG(1) << "Extension " << id << " is not a theme; aborting";
         return;
       }
-      if (!extensions_service->IsExtensionEnabled(id)) {
-        DVLOG(1) << "Theme " << id << " is not enabled; aborting";
+      int disabled_reasons =
+          extensions_service->extension_prefs()->GetDisableReasons(id);
+      if (!extensions_service->IsExtensionEnabled(id) &&
+          disabled_reasons != extensions::Extension::DISABLE_USER_ACTION) {
+        DVLOG(1) << "Theme " << id << " is disabled with reason "
+                 << disabled_reasons << "; aborting";
         return;
       }
       // An enabled theme extension with the given id was found, so
       // just set the current theme to it.
       theme_service_->SetTheme(extension);
     } else {
       // No extension with this id exists -- we must install it; we do
       // so by adding it as a pending extension and then triggering an
       // auto-update cycle.
       const bool kInstallSilently = true;
@@ skipping 97 matching lines @@
       syncer::SyncChange(FROM_HERE, change_type,
                          syncer::SyncData::CreateLocalData(
                              kCurrentThemeClientTag, kCurrentThemeNodeTitle,
                              entity_specifics)));
 
   DVLOG(1) << "Update theme specifics from current theme: "
       << changes.back().ToString();
 
   return sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
 }