headless: Remove old load observer API

headless/lib/browser/headless_devtools_client_impl.cc

 // Copyright 2016 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 "headless/lib/browser/headless_devtools_client_impl.h"
 
 #include <memory>
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
@@ skipping 84 matching lines @@
 bool HeadlessDevToolsClientImpl::DispatchMessageReply(
     const base::DictionaryValue& message_dict) {
   int id = 0;
   if (!message_dict.GetInteger("id", &id))
     return false;
   auto it = pending_messages_.find(id);
   if (it == pending_messages_.end()) {
     NOTREACHED() << "Unexpected reply";
     return false;
   }
-  if (!it->second.callback_with_result.is_null()) {
+  Callback callback = std::move(it->second);
+  pending_messages_.erase(it);
+  if (!callback.callback_with_result.is_null()) {
     const base::DictionaryValue* result_dict;
     if (!message_dict.GetDictionary("result", &result_dict)) {
       NOTREACHED() << "Badly formed reply result";
       return false;
     }
-    it->second.callback_with_result.Run(*result_dict);
-  } else if (!it->second.callback.is_null()) {
-    it->second.callback.Run();
+    callback.callback_with_result.Run(*result_dict);
+  } else if (!callback.callback.is_null()) {
+    callback.callback.Run();
   }
-  pending_messages_.erase(it);
   return true;
 }
 
 bool HeadlessDevToolsClientImpl::DispatchEvent(
     const base::DictionaryValue& message_dict) {
   std::string method;
   if (!message_dict.GetString("method", &method))
     return false;
   auto it = event_handlers_.find(method);
   if (it == event_handlers_.end()) {
@@ skipping 210 matching lines @@
 HeadlessDevToolsClientImpl::Callback::Callback(
     base::Callback<void(const base::Value&)> callback)
     : callback_with_result(callback) {}
 
 HeadlessDevToolsClientImpl::Callback::~Callback() {}
 
 HeadlessDevToolsClientImpl::Callback& HeadlessDevToolsClientImpl::Callback::
 operator=(Callback&& other) = default;
 
 }  // namespace headless