Remove use of deprecated base::ListValue::Append(Value*) overload in extensions.

extensions/browser/api/web_request/web_request_api_helpers.h

 // 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.
 
 // Helper classes and functions used for the WebRequest API.
 
 #ifndef EXTENSIONS_BROWSER_API_WEB_REQUEST_WEB_REQUEST_API_HELPERS_H_
 #define EXTENSIONS_BROWSER_API_WEB_REQUEST_WEB_REQUEST_API_HELPERS_H_
 
 #include <list>
@@ skipping 324 matching lines @@
 // given |browser_context_id| to collect UMA statistics on Page Load Times.
 // Needs to be called on the UI thread.
 void NotifyWebRequestAPIUsed(void* browser_context_id,
                              const std::string& extension_id);
 
 // Send updates to |host| with information about what webRequest-related
 // extensions are installed.
 void SendExtensionWebRequestStatusToHost(content::RenderProcessHost* host);
 
 // Converts the |name|, |value| pair of a http header to a HttpHeaders
-// dictionary. Ownership is passed to the caller.
-base::DictionaryValue* CreateHeaderDictionary(
-    const std::string& name, const std::string& value);
+// dictionary.
+std::unique_ptr<base::DictionaryValue> CreateHeaderDictionary(
+    const std::string& name,
+    const std::string& value);
 
 // Returns whether |type| is a ResourceType that is handled by the web request
 // API.
 bool IsRelevantResourceType(content::ResourceType type);
 
 // Returns a string representation of |type| or |other| if |type| is not handled
 // by the web request API.
 const char* ResourceTypeToString(content::ResourceType type);
 
 // Stores a |content::ResourceType| representation in |types| if |type_str| is
 // a resource type handled by the web request API. Returns true in case of
 // success.
 bool ParseResourceType(const std::string& type_str,
                        std::vector<content::ResourceType>* types);
 
 }  // namespace extension_web_request_api_helpers
 
 #endif  // EXTENSIONS_BROWSER_API_WEB_REQUEST_WEB_REQUEST_API_HELPERS_H_