Create --disable-extensions-except switch

chrome/browser/extensions/extension_service.cc

Index: chrome/browser/extensions/extension_service.cc
diff --git a/chrome/browser/extensions/extension_service.cc b/chrome/browser/extensions/extension_service.cc
index bb578e1db6ae68b13e19757e9bcfddd83cafeeee..5e0c638795ba7aae9b5eda9c47b9161e6d2dff52 100644
--- a/chrome/browser/extensions/extension_service.cc
+++ b/chrome/browser/extensions/extension_service.cc
@@ -1446,10 +1446,10 @@ 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() &&
+  if (!extensions_enabled() && !extension->is_theme() &&
       extension->location() != Manifest::COMPONENT &&
-      !Manifest::IsExternalLocation(extension->location())) {
+      !Manifest::IsExternalLocation(extension->location()) &&
+      !IsExtensionWhitelisted(extension->id())) {
     return;
   }