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

extensions/browser/api/web_request/web_request_api_helpers.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 "extensions/browser/api/web_request/web_request_api_helpers.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 1257 matching lines @@
   for (extensions::ExtensionSet::const_iterator it = extensions.begin();
        !webrequest_used && it != extensions.end();
        ++it) {
     webrequest_used |= runtime_data->HasUsedWebRequest((*it)->id());
   }
 
   host->Send(new ExtensionMsg_UsingWebRequestAPI(webrequest_used));
 }
 
 // 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) {
-  base::DictionaryValue* header = new base::DictionaryValue();
+// dictionary.
+std::unique_ptr<base::DictionaryValue> CreateHeaderDictionary(
+    const std::string& name,
+    const std::string& value) {
+  std::unique_ptr<base::DictionaryValue> header(new base::DictionaryValue());
   header->SetString(keys::kHeaderNameKey, name);
   if (base::IsStringUTF8(value)) {
     header->SetString(keys::kHeaderValueKey, value);
   } else {
     header->Set(keys::kHeaderBinaryValueKey,
                 StringToCharList(value));
   }
   return header;
 }
 
@@ skipping 22 matching lines @@
   for (size_t i = 0; i < kResourceTypeStringsLength; ++i) {
     if (type_str == kResourceTypeStrings[i]) {
       found = true;
       types->push_back(kResourceTypeValues[i]);
     }
   }
   return found;
 }
 
 }  // namespace extension_web_request_api_helpers