Change ThemeService to handle uninstalled themes.

chrome/browser/extensions/extension_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/extensions/extension_service.h"
 
 #include <algorithm>
 #include <set>
 
 #include "base/basictypes.h"
@@ skipping 1144 matching lines @@
 
 void ExtensionService::NotifyExtensionUnloaded(
     const Extension* extension,
     extension_misc::UnloadedExtensionReason reason) {
   UnloadedExtensionInfo details(extension, reason);
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_EXTENSION_UNLOADED,
       content::Source<Profile>(profile_),
       content::Details<UnloadedExtensionInfo>(&details));
 
+#if defined(ENABLE_THEMES)
+  // If the current theme is being unloaded, tell ThemeService to revert back
+  // to the default theme.
+  if (reason != extension_misc::UNLOAD_REASON_UPDATE && extension->is_theme()) {
+    ThemeService* theme_service = ThemeServiceFactory::GetForProfile(profile_);
+    if (extension->id() == theme_service->GetThemeID())
+      theme_service->UseDefaultTheme();
+  }
+#endif
+
   for (content::RenderProcessHost::iterator i(
           content::RenderProcessHost::AllHostsIterator());
        !i.IsAtEnd(); i.Advance()) {
     content::RenderProcessHost* host = i.GetCurrentValue();
     Profile* host_profile =
         Profile::FromBrowserContext(host->GetBrowserContext());
     if (host_profile->GetOriginalProfile() == profile_->GetOriginalProfile())
       host->Send(new ExtensionMsg_Unloaded(extension->id()));
   }
 
@@ skipping 1856 matching lines @@
         extension_id, kOnUpdateAvailableEvent);
   } else {
     // Delay installation if the extension is not idle.
     return !IsExtensionIdle(extension_id);
   }
 }
 
 void ExtensionService::OnBlacklistUpdated() {
   CheckManagementPolicy();
 }