Add DCHECKs to StatefulExternalExtensionProvider

chrome/browser/extensions/external_policy_extension_provider_unittest.cc

 // Copyright (c) 2010 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 <string>
 
 #include "base/logging.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "chrome/browser/extensions/external_policy_extension_provider.h"
 #include "chrome/common/extensions/extension.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 class ExternalPolicyExtensionProviderTest : public testing::Test {
 };
 
 class MockExternalPolicyExtensionProviderVisitor
     : public ExternalExtensionProvider::Visitor {
  public:
   MockExternalPolicyExtensionProviderVisitor() {
   }
 
   // Initialize a provider with |policy_forcelist|, and check that it parses
   // exactly those extensions, that are specified in |policy_validlist|.
   void Visit(ListValue* policy_forcelist,
              ListValue* policy_validlist,
              const std::set<std::string>& ignore_list) {
-    provider_.reset(new ExternalPolicyExtensionProvider());
-    // Give the list extensions to the provider.
-    provider_->SetPreferences(policy_forcelist);
+    provider_.reset(new ExternalPolicyExtensionProvider(policy_forcelist));
 
     // Extensions will be removed from this list as they visited,
     // so it should be emptied by the end.
     remaining_extensions = policy_validlist;
     provider_->VisitRegisteredExtension(this);
     EXPECT_EQ(0u, remaining_extensions->GetSize());
   }
 
   virtual void OnExternalExtensionFileFound(const std::string& id,
                                             const Version* version,
@@ skipping 63 matching lines @@
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa;http#//www.example.com/crx"));
   forced_extensions.Append(Value::CreateStringValue(
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"));
   forced_extensions.Append(Value::CreateStringValue(
       "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaahttp#//www.example.com/crx"));
 
   MockExternalPolicyExtensionProviderVisitor mv;
   std::set<std::string> empty;
   mv.Visit(&forced_extensions, &valid_extensions, empty);
 }