base: Add AsList() function to Value API.

chrome/test/automation/javascript_execution_controller.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 "chrome/test/automation/javascript_execution_controller.h"
 
 #include "chrome/test/automation/javascript_message_utils.h"
 #include "content/common/json_value_serializer.h"
 
 using javascript_utils::JavaScriptPrintf;
@@ skipping 71 matching lines @@
       LOG(ERROR) << "Cannot parse JSON response: " << parsing_error;
     } else {
       LOG(ERROR) << "JSON response is empty";
     }
     return false;
   }
 
   bool success;
   std::string evaluation_error;
   Value* evaluation_result_value;
-  if (!root_value->IsType(Value::TYPE_LIST)) {
+  ListValue* list = root_value.AsList();
+  if (!list) {
     LOG(ERROR) << "JSON response was not in correct format";
     return false;
   }
-  ListValue* list = static_cast<ListValue*>(root_value.get());
   if (!list->GetBoolean(0, &success) ||
       !list->GetString(1, &evaluation_error) ||
       !list->Remove(2, &evaluation_result_value)) {
     LOG(ERROR) << "JSON response was not in correct format";
     return false;
   }
   if (!success) {
     LOG(WARNING) << "JavaScript evaluation did not complete successfully: "
                  << evaluation_error;
     return false;
   }
   result->reset(evaluation_result_value);
   return true;
 }