Refactor the various ways to control what users can do to extensions.

chrome/browser/extensions/test_extension_system.cc

Index: chrome/browser/extensions/test_extension_system.cc
===================================================================
--- chrome/browser/extensions/test_extension_system.cc	(revision 140193)
+++ chrome/browser/extensions/test_extension_system.cc	(working copy)
@@ -64,10 +64,22 @@
   return extension_service_.get();
 }
 
+extensions::ManagementPolicy* TestExtensionSystem::CreateManagementPolicy() {
+  management_policy_.reset(new extensions::ManagementPolicy());
+  DCHECK(extension_prefs_.get());
+  management_policy_->RegisterProvider(extension_prefs_.get());
+
+  return management_policy();
+}
+
 ExtensionService* TestExtensionSystem::extension_service() {
   return extension_service_.get();
 }
 
+extensions::ManagementPolicy* TestExtensionSystem::management_policy() {
+  return management_policy_.get();
+}
+
 void TestExtensionSystem::SetExtensionService(ExtensionService* service) {
   extension_service_.reset(service);
 }