base: Add AsList() function to Value API.

chrome/test/automation/javascript_execution_controller.cc

Index: chrome/test/automation/javascript_execution_controller.cc
diff --git a/chrome/test/automation/javascript_execution_controller.cc b/chrome/test/automation/javascript_execution_controller.cc
index 5be6b983fb7647993aa1d6fdae3923c185569679..9a962b68df694edcfd71858473e5a0436268e059 100644
--- a/chrome/test/automation/javascript_execution_controller.cc
+++ b/chrome/test/automation/javascript_execution_controller.cc
@@ -89,11 +89,11 @@ bool JavaScriptExecutionController::ExecuteAndParseHelper(
   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)) {